PROTEIN COMPLEX INCLUDING BOTULINUM TOXIN TRANSLOCATION DOMAIN AND ENDOLYSIN AND ANTIBACTERIAL COMPOSITION INCLUDING SAME

Abstract

Provided is a protein complex including a botulinum toxin translocation domain and endolysin. When used, the protein complex including a botulinum translocation domain and endolysin according to the present invention exhibits an antibacterial effect and thus can be used as an antibacterial composition or an antibiotic.

Claims

1.-10. (canceled)

11. An antibacterial composition comprising a protein complex comprising a botulinum toxin translocation domain and endolysin.

12. (canceled)

13. The antibacterial composition according to claim 11, wherein the botulinum toxin translocation domain is connected to a C-terminus of the endolysin.

14. The antibacterial composition according to claim 11 further comprising a receptor-binding protein.

15. The antibacterial composition according to claim 14, wherein the botulinum toxin translocation domain is connected to a C-terminus of the endolysin, and the receptor-binding protein is connected to a C-terminus of the botulinum toxin translocation domain.

16. The antibacterial composition according to claim 11, wherein the antibacterial composition has a lytic effect on Gram-negative bacteria.

Description

DESCRIPTION OF DRAWINGS

[0030] FIG. 1 illustrates a vector for producing full-length translysin.

[0031] FIG. 2 illustrates the result of detection of translysin by SDS gel electrophoresis.

[0032] FIG. 3 illustrates the result of detection of innolysin by SDS gel electrophoresis.

[0033] FIG. 4 shows lytic effects depending on the presence or absence of intracellular expression of translysin and innolysin, as detected from the turbidity of a culture solution.

[0034] FIG. 5 is a graph showing growth patterns depending on the presence or absence of intracellular expression of translysin, innolysin, and endolysin, as detected from turbidity of the culture medium.

[0035] FIG. 6(A) shows four protein fragments (LysPA26-Gp41.1N, PB1_gp48-Gp41.1N, Gp41.1C-iLCH.sub.N-CfaN, CfaC-PRD1_04) used to produce translysin. FIG. 6(B) shows three protein fragments (LysPA26-Gp41.1N, Gp41.1C-iLCH.sub.N-Spy.sup.C003, Spy.sup.T003-PRD1_04) used to produce translysin.

[0036] FIG. 7 shows the result of trans-splicing of PB1_gp48 and iLCH.sub.N over time.

[0037] FIG. 8 shows the result of trans-splicing of LysPA26 and iLCH.sub.N over time.

[0038] FIG. 9 shows the result of trans-splicing of iLCH.sub.N and PRD1 over time.

[0039] FIG. 10 shows the result of trans-splicing of PB1_gp48, iLCH.sub.N and PRD1 over time.

[0040] FIG. 11 shows the results of trans-splicing and bioconjugation of LysPA26, iLCH.sub.N, and PRD1 over time.

[0041] FIG. 12 is a schematic diagram illustrating a method of performing a spotting assay.

[0042] FIG. 13 shows the lytic activity of the LysPA26-Gp41.1N fragment against dead cells, detected by spotting assay.

[0043] FIG. 14 shows the lytic activity of the PB1_gp48-Gp41.1N fragment against dead cells, detected by spotting assay.

[0044] FIG. 15 shows the lytic activity of translysin (LysPA26-iLCH.sub.N-PRD1) and endolysin fragments against live bacteria, detected by spotting assay.

[0045] FIG. 16 shows the lytic activity of translysin (PB1_gp48-iLCH.sub.N-PRD1) and endolysin fragments against live bacteria, detected by spotting assay.

[0046] FIG. 17 shows the lytic activity of translysin (PB1_gp48-iLCH.sub.N-PRD1) and endolysin fragments, and innolysin against live bacteria, detected by spotting assay.

[0047] FIG. 18 shows the lytic activity of translysin (LysPA26-iLCH.sub.N-PRD1) and endolysin fragments, and innolysin against live bacteria, detected by spotting assay.

[0048] FIG. 19 is an electron microscope image showing viable cells depending on the translysin treatment and time.

[0049] FIG. 20 shows the lytic activity of translysin and innolysin detected through CFU reduction assay.

[0050] FIG. 21 shows a schematic diagram illustrating screening of a translysin library against target strains.

[0051] FIG. 22 shows the lysis patterns of viable cells of target strains as a function of concentration of each translysin.

[0052] FIG. 23 is a schematic diagram illustrating the translysin structure of the present invention.

[0053] FIG. 24 is a schematic diagram illustrating the mechanism of action of translysin of the present invention.

[0054] FIG. 25 is a schematic diagram illustrating a method for synthesizing translysin using intein.

[0055] FIG. 26 is a schematic diagram illustrating a translysin synthesis method using intein and SpyTag and Spycatcher.

BEST MODE

[0056] In one aspect, the present invention is directed to a protein complex containing a botulinum toxin translocation domain and endolysin.

[0057] As used herein, the term protein complex may be used interchangeably with translysin.

[0058] As used herein, the term botulinum toxin translocation domain refers to a protein that has the function of delivering light chains of botulinum toxin into nerve cells, and the delivery process occurs based on the mechanism in which when the botulinum toxin is introduced into the cells through endocytosis, the inside of the endosome becomes acidic, causing the translocation domain to have enzymatic activity, resulting in the process of transferring light chains from the endosome to the cytoplasm. As used herein, the term botulinum toxin translocation domain may also be referred to as botulinum toxin translocation domain H.sub.N, translocation domain, H.sub.N, or the like. In the present invention, the botulinum toxin translocation domain serves to allow the protein complex of the present invention to pass through the cell membrane (outer cell membrane). As a result, the protein complex of the present invention can access the peptidoglycan that exists between the outer and inner cell membranes.

[0059] In one embodiment of the present invention, the botulinum toxin translocation domain may include at least one amino acid sequence selected from SEQ ID NOS: 29, 38, and 39.

[0060] As used herein, the expression that polynucleotide (that may be used interchangeably with gene) or polypeptide (that may be used interchangeably with protein) includes a specific nucleic acid sequence or amino acid sequence or includes a specific nucleic acid sequence or amino acid sequence. may mean that the polynucleotide or polypeptide essentially includes the specific nucleic acid sequence or amino acid sequence, and may be interpreted as including a substantially identical sequence including a mutated (deleted, substituted, modified, and/or added) specific nucleic acid sequence or amino acid sequence (or not excluding the mutation) while maintaining the original function and/or desired function of the polynucleotide or polypeptide. For example, the expression that a polynucleotide or polypeptide includes a specific nucleic acid sequence or amino acid sequence or includes or is represented by a specific nucleic acid sequence or amino acid sequence means that the polynucleotide or polypeptide (i) essentially includes a sequence or amino acid sequence, or (ii) includes an amino acid sequence having an identity of at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%, or at least 99.9% to the specific nucleic acid or amino acid sequence and maintains original and/or desired functions thereof.

[0061] In one embodiment of the present invention, the protein complex may further contain a botulinum toxin light chain (LC). The addition of the botulinum toxin light chain (LC) may facilitate expression of the botulinum toxin translocation domain in a soluble form. At this time, it is preferable to use the botulinum toxin light chain in an inactivated state. According to an embodiment of the present invention, the botulinum toxin light chain may be obtained in an inactive form by modifying a zinc-binding sequence.

[0062] In one embodiment of the present invention, the inactivated botulinum toxin light chain (iLC) may include at least one selected from amino acid sequences represented by SEQ ID NOS: 30, 40, and 41 and the like.

[0063] In one embodiment of the present invention, the botulinum toxin translocation domain may be linked to the inactivated botulinum toxin light chain (iLC).

[0064] In one embodiment of the present invention, the polypeptide including the botulinum toxin translocation domain and the inactivated botulinum toxin light chain linked to each other may include an amino acid sequence of SEQ ID NO: 31.

[0065] As used herein, the term endolysin refers to a protein expressed in a virus that causes infection with bacteria as a host, and the endolysin exhibits the activity of lysing the cell wall of the host bacteria. Since endolysin cannot penetrate the outer cell membrane by itself, only the lytic activity of endolysin against Gram-positive bacteria is known. In addition, endolysin is not cytotoxic to eukaryotes including humans because it uses bacterial peptidoglycan as a substrate, and no cases of bacteria resistant to endolysin have been reported.

[0066] In the present invention, the protein complex of the present invention, which passes through the outer cell membrane and accesses peptidoglycan through the botulinum toxin translocation domain decomposes peptidoglycan through the endolysin contained therein and thus exhibits antibacterial activity.

[0067] In one embodiment of the present invention, the endolysin is selected from the group consisting of lys, LysPA26, PB1_gp48, LysAB2_P3, PlyF307, AcLys, PlyPA03, PlyPA91, Abtn-4, WCHABP1_gp01, WCHABP12_gp19, gh-1p12, B3ORF25, phi-13Sp4, phi-6S_4, KP27_166, KP13_gp066, BI057_gp221, LPSE_00024, STP4a_120, Lys68, SPN1S_0028 and P22gp66. However, any endolysin may be used in the present invention so long as it exhibit lytic activity and the endolysin is not necessarily limited to a specific type.

[0068] In one embodiment of the present invention, the protein complex may further contain a receptor-binding protein.

[0069] As used herein, the term receptor-binding protein refers to a structural protein involved in the process of recognizing and attaching to a specific receptor on the cell wall when a bacteriophage infects a host cell. The receptor-binding protein plays a role in maintaining stable binding while the genetic material of the bacteriophage is transferred into the host cell during the infection process and is known to be capable of binding to both gram-negative and gram-positive bacteria. Therefore, the present invention increases the contact of the protein complex with the strains and protein transfer efficiency using the characteristics of the receptor-binding protein. In other words, the present invention includes a receptor-binding protein and thus the protein complex of the present invention can be more easily and strongly bound to the target microorganism to be killed.

[0070] In one embodiment of the present invention, the receptor-binding protein may be selected from the group consisting of PRD1_04, P1301_0153, P24_0149, Pb5, AbTJ_gp52, AbTJ_gp53, phiAB6_gp40, S, A318_gp060, rv5_gp030, rv5_gp033, PaoP5_075, BH773_gp153, AU075_gp145, CPT_Sugarland_191, JIPhKp127_0170, AmPhEK80_0178, P22_gp19, DET7_207, HWD08_gp154, BI021_gp088, HWD21_gp023, HWC41_gp146, HOS12_gp017, HOU44_gp075, I133_gp019, HWC50_gp066 and HOS34_gp106. Any receptor-binding protein may be used so long as it can interact with the target strain and the receptor-binding protein is not necessarily limited to a specific type.

[0071] In one embodiment of the present invention, the protein complex has a configuration in which the endolysin, the botulinum toxin translocation domain, and the receptor-binding protein are disposed in this order.

[0072] In one embodiment of the present invention, the protein complex preferably has a configuration in which the endolysin, the botulinum toxin translocation domain, and the receptor-binding protein are disposed in this order from the amino terminus to the carboxyl terminus.

[0073] In one embodiment of the present invention, the protein complex has a configuration in which the endolysin, the botulinum toxin light chain, the botulinum toxin translocation domain, and the receptor-binding protein are disposed in this order from the amino terminus to the carboxyl terminus.

[0074] However, the order of the configuration of the protein complex described above is provided only as an example and thus the order of configuration is not limited thereto.

[0075] In one embodiment of the present invention, preferably, the protein complex has a configuration in which endolysin binds to the amino terminus of the botulinum toxin translocation domain and the receptor-binding protein binds to the carboxyl terminus of the botulinum toxin translocation domain.

[0076] In another aspect, the present invention is directed to a recombinant vector containing a polynucleotide encoding the protein complex.

[0077] As used herein, the term vector means a nucleic acid that includes a competent nucleotide sequence that is inserted into a host cell and recombines with and integrates into the host cell genome, or that replicates spontaneously as an episome. These vectors include linear nucleic acids, plasmids, phagemids, cosmids, RNA vectors, viral vectors and the like.

[0078] In another aspect, the present invention is directed to a host cell transformed with the recombinant vector containing the polynucleotide encoding the protein complex. The polynucleotide may include a nucleic acid sequence represented by SEQ ID NO: 21.

[0079] Host cells include cells that have been transfected, transformed, or infected with a recombinant vector or polynucleotide of the present invention, either in vivo or in vitro. The host cell containing the recombinant vector of the present invention is a recombinant host cell, a recombinant cell, a recombinant microorganism, or a mutant microorganism.

[0080] As used herein, the term transformation means a phenomenon in which DNA that is introduced into a host can be replicated with an extrachromosomal factor or by insertion into the chromosome.

[0081] As used herein, the term encoded by or encoding means that a polynucleotide expresses a polypeptide sequence.

[0082] In accordance with another aspect of the present invention, provided is a method of preparing a protein complex including mixing a first protein fragment containing a botulinum toxin translocation domain with a second protein fragment containing endolysin (a), and linking the mixed protein fragments to each other (b).

[0083] In one embodiment of the present invention, the method may further include mixing a third protein fragment containing a receptor-binding protein in the step (a) of mixing the first protein fragment containing the botulinum toxin translocation domain with the second protein fragment containing endolysin.

[0084] In one embodiment of the present invention, in the step of mixing (a), the first protein fragment containing the botulinum toxin translocation domain, the second protein fragment containing endolysin, and the third protein fragment containing the receptor-binding protein are mixed at a molar ratio of 1-5:1-5:1-5. According to an embodiment of the present invention, the mixing is preferably performed by mixing the first protein fragment, the second protein fragment, and the third protein fragment at a molar ratio of 1:1:1.

[0085] In the present invention, there is no limitation as to the order of mixing the protein fragments in the method for producing the protein complex. For example, the protein complex may be produced by mixing the first protein fragment containing the botulinum toxin translocation domain with the third protein fragment containing the receptor-binding protein, performing reaction, mixing the resulting product with the second protein fragment containing endolysin, and then performing reaction.

[0086] The botulinum toxin translocation domain, endolysin, and receptor-binding protein of the present invention are incorporated in the protein complex of one embodiment of the present invention and thus duplicate description is omitted to avoid excessive redundancy in the present specification.

[0087] In one embodiment of the present invention, the protein fragments, that is, the first protein fragment, the second protein fragment, and the third protein fragment, may include an intein. The intein is responsible for the reaction in which the two fragments of the split intein, Int.sup.N and Int.sup.C, spontaneously form a peptide bond and bind the extein linked to each fragment. The intein bound in this process is separated and removed from the newly bound extein. The protein binding reaction by inteins is referred to as protein trans-splicing.

[0088] In one embodiment of the present invention, the first protein fragment includes different types of inteins, namely, IntA.sup.C and IntB.sup.N, at both ends of the botulinum toxin translocation domain, the second protein fragment includes IntA.sup.N and endolysin, and the third protein fragment includes receptor-binding protein and IntB.sup.C. The Int.sup.A and Int.sup.B mean that they are different types of inteins.

[0089] In one embodiment of the present invention, the botulinum toxin translocation domain, endolysin, receptor-binding protein, and intein of the protein fragment may be linked by a linker.

[0090] As used herein, the term linker refers to a peptide inserted between two proteins, which are linked to produce another protein, in order to increase the structural flexibility of the proteins or enhance the activity of each protein. Any linker may be used without limitation as long as it does not inhibit the activity of each protein to be fused and does not cause an unnecessary immune response. The linker may be selected from the group consisting of a flexible amino acid linker, an inflexible linker, a cleavable amino acid linker, and a compound linker.

[0091] In one embodiment of the present invention, the intein may be selected from the group consisting of Gp41.1, Cfa, NRDJ-1, IMPDH-1, Npu, Ssp, Rma, Ppu, Gp41.8, and NrdA-2.

[0092] In one embodiment of the present invention, the step of linking the protein fragments may be performed by a protein trans-splicing reaction.

[0093] In one embodiment of the present invention, the protein fragment may include SpyTag and Spycatcher. SpyTag and SpyCatcher are used for irreversible conjugation of recombinant proteins. SpyTag and SpyCatcher spontaneously react with each other to form an intermolecular isopeptide bond therebetween and thereby enable bioconjugation between two recombinant proteins. According to the present invention, the SpyCatcher is present at the C terminus of the botulinum toxin translocation domain, the SpyTag is present in the receptor-binding protein, and the efficiency of binding between receptor-binding protein and the botulinum toxin translocation domain can be improved through the isopeptide bond of the SpyCatcher and SpyTag.

[0094] In one embodiment of the present invention, the step of linking the protein fragments may be performed by bioconjugation. Bioconjugation is a chemical reaction that links two biomolecules to each other, is generally a protein-protein conjugation, and serves as a key strategy for linking biomolecules to other substrates. Examples of bioconjugation include coupling of lysine, cysteine, and tyrosine amino acid residues, modification of tryptophan amino acid residues, and modification of the N- and C-termini. In the present invention, as described above, the binding efficiency between the botulinum toxin translocation domain and the receptor-binding protein is increased through the isopeptide bond between the SpyCatcher and the SpyTag.

[0095] In another aspect, the present invention is directed to an antibacterial composition containing the protein complex. At this time, the pH of the antibacterial composition is preferably adjusted to 7.4, and the antibacterial composition is not limited to any conditions known in the art. The antibacterial composition of the present invention exhibits antibacterial activity against Gram-positive and Gram-negative bacteria.

[0096] The gram-positive bacteria may be Gram-positive bacteria including Staphylococcus, Listeria, Streptococcus, Corynebacterium, Lactobacillus, Clostridium, Enterococcus, Erysipelothrix, and Bacillus, and may include all Gram-positive bacteria known in the art.

[0097] The gram-negative bacteria may be Gram-negative bacteria including Escherichia, Pseudomonas, Salmonella, Leptospira, Klebsiella, Helicobacter, and Enterobacter, and may include all Gram-negative bacteria known in the art.

[0098] The antibacterial composition of the present invention exhibits antibacterial activity against the following pathogens, but is not limited thereto:

[0099] Acinetobacter baumannii, Actinomyces sp. (for example, Actinomyces israelii and Actinomyces naeslundii, Aeromonas sp. (for example, Aeromonas hydrophila, Aeromonas veronii biovar sobria (Aeromonas sobria)) and Aeromonas caviae, Anaplasma phagocytophilum, Alcaligenes xylosoxidans, Actinobacillus actinomycetemcomitans, Bacillus sp. (for example, Bacillus anthracis, Bacillus cereus, Bacillus subtilis, Bacillus thuringiensis, and Bacillus stearothermophilus, Bacteroides sp. (for example, Bacteroides fragilis, Bartonella sp. (for example, Bartonella bacilliformis and Bartonella henselae, Bifidobacterium sp., Bordetella sp. (for example Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica, Borrelia sp. (for example, Borrelia recurrentis and Borrelia burgdorferi, Brucella sp. (for example, Brucella abortus, Brucella canis, Brucella melintensis and Brucella suis, Burkholderia sp. (for example, Burkholderia pseudomallei, and Burkholderia cepacia, Campylobacter sp. (for example, Campylobacter jejuni, Campylobacter coli, Campylobacter lar, and Campylobacter fetus, Capnocytophaga sp., Cardiobacterium hominis, Chlamydia trachomatis, Chlamydophila pneumonia, Chlamydophila psittaci, Citrobacter sp. Coxiella burnetii, Corynebacterium sp. (for example, Corynebacterium diphtheria), Corynebacterium jeikeum, and Corynebacterium, Clostridium sp. (for example, Clostridium perfringens, Clostridium difficile, Clostridium botulinum, and Clostridium tetani, Eikenella corrodens, Enterobacter sp. (for example, Enterobacter aerogenes, Enterobacter agglomerans, Enterobacter cloacae, and enterotoxigenic E. coli, enteroinvasive E. coli, enteropathogenic E. coli, enterohemorrhagic E. coli, enteroaggregative E. coli, and Escherichia coli including opportunistic E. coli such as uropathogenic E. coli, Enterococcus sp. (for example Enterococcus faecalis and Enterococcus faecium), Ehrlichia sp. (for example, Ehrlichia chafeensia and Ehrlichia canis, Erysipelothrix rhusiopathiae, Eubacterium sp., Francisella tularensis, Fusobacterium nucleatum, Gardnerella vaginalis, Gemella morbillorum, Haemophilus sp. (for example, Haemophilus influenzae, Haemophilus ducreyi, Haemophilus aegyptius, Haemophilus parainfluenzae, Haemophilus haemolyticus, and Haemophilus parahaemolyticus, Helicobacter sp. for example, Helicobacter pylori, Helicobacter cinaedi, and Helicobacter fennelliae, Kingella kingii, Klebsiella sp. (for example, Klebsiella pneumoniae, Klebsiella granulomatis, and Klebsiella oxytoca, Lactobacillus sp., Listeria monocytogenes, Leptospira interrogans, Legionella pneumophila, Leptospira interrogans, Peptostreptococcus sp., Moraxella catarrhalis, Morganella sp., Mobiluncus sp., Micrococcus sp., Mycobacterium sp. for example, Mycobacterium leprae, Mycobacterium intracellulare, Mycobacterium avium, Mycobacterium bovis, and Mycobacterium marinum, Mycoplasm sp. (for example, Mycoplasma pneumoniae, Mycoplasma hominis, and Mycoplasma genitalium, Nocardia sp. (for example, Nocardia asteroides, Nocardia cyriacigeorgica, and Nocardia brasiliensis, Neisseria sp. (for example, Neisseria gonorrhoeae, and Neisseria meningitidis, Pasteurella multocida, Plesiomonas shigelloides, Prevotella sp., Porphyromonas sp., Prevotella melaninogenica, Proteus sp. (for example, Proteus vulgaris and Proteus mirabilis, Providencia sp. (for example, Providencia alcalifaciens, Providencia rettgeri, and Providencia stuartii, Pseudomonas aeruginosa, Propionibacterium acnes, Rhodococcus equi, Salmonella sp. (for example, Salmonella enterica, Salmonella typhi, Salmonella paratyphi, Salmonella enteritidis, Salmonella cholerasuis, and Salmonella typhimurium, Serratia sp. (for example, Serratia marcesans, and Serratia liquifaciens, Shigella sp. (for example, Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei, Staphylococcus sp. (for example, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hemolyticus, Staphylococcus saprophyticus, Streptococcus sp. (for example, Streptococcus pneumoniae, Spectinomycin-resistant serotype 6B Streptococcus pneumoniae, Streptomycin-resistant serotype 9V Streptococcus pneumoniae, Erythromycin-resistant serotype 14 Streptococcus pneumoniae, Optochin-resistant serotype 14 Streptococcus pneumoniae, Rifampicin-resistant serotype 18C Streptococcus pneumoniae, Tetracycline-resistant serotype 19F Streptococcus pneumoniae, Penicillin-resistant serotype 19F Streptococcus pneumoniae and Trimethoprim-resistant serotype 23F Streptococcus pneumoniae, Chloramphenicol-resistant serotype 4 Streptococcus pneumoniae, Streptomycin-resistant serotype 9V Streptococcus pneumoniae, Optochin-resistant serotype 14 Streptococcus pneumoniae, Rifampicin-resistant serotype 18C Streptococcus pneumoniae, Penicillin-resistant serotype 19F Streptococcus pneumoniae) or Trimethoprim-resistant serotype 23F Streptococcus pneumoniae, Streptococcus agalactiae, Streptococcus mutans, Streptococcus pyogenes, Group A streptococci, Streptococcus pyogenes, Group B streptococci, Streptococcus agalactiae, Group C streptococci, Streptococcus anginosus, Streptococcus equisimilis, Group D streptococci, Streptococcus bovis, Group F streptococci and Streptococcus anginosus, Group G streptococci, Spirillum minus, Streptobacillus moniliformi, Treponema sp. (for example, Treponema carateum, Treponema petenue, Treponema pallidum, and Treponema endemicum, Tropheryma whippelii, Ureaplasma urealyticum, Veillonella sp., Vibrio sp. (for example, Vibrio cholerae, Vibrio parahemolyticus, Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio alginolyticus, Vibrio mimicus, Vibrio hollisae, Vibrio fluvialis, Vibrio metchnikovii, Vibrio damsela and Vibrio furnisii, Yersinia sp. (for example, Yersinia enterocolitica and Yersinia pestis and Xanthomonas maltophilia).

[0100] In one embodiment of the present invention, the antibacterial composition is an antibacterial pharmaceutical composition.

[0101] The pharmaceutical composition of the present invention may further contain a pharmaceutically acceptable carrier in addition to the composition as an active ingredient.

[0102] The pharmaceutically acceptable additive contained in the pharmaceutical composition of the present invention may be commonly used in the formulation and includes, but is not limited to, lactose, dextrose, sucrose, sorbitol, mannitol, starch, acacia gum, calcium phosphate, alginate, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, methyl cellulose, methyl hydroxybenzoate, propyl hydroxybenzoate, talc, magnesium stearate and mineral oil.

[0103] In addition to the ingredients, the pharmaceutical composition of the present invention may further contain lubricants, wetting agents, sweeteners, flavoring agents, emulsifiers, suspending agents, preservatives, or the like. Suitable pharmaceutically acceptable carriers and agents are described in detail in Remington's Pharmaceutical Sciences (19th ed., 1995).

[0104] The pharmaceutical composition of the present invention may be administered orally or parenterally, for example, intrathecally, intravenously, subcutaneously, intradermally, intramuscularly, intraperitoneally, intrasternally, intratumorally, intranasally, intracerebrally, intracranially, intrapulmonarily, and intrarectally, but is not limited thereto.

[0105] That is, the pharmaceutically effective amount of the pharmaceutical composition of the present invention may vary depending on the formulation method, administration method, age, weight, gender, pathological condition, diet, administration time, administration route, excretion rate and reaction sensitivity of the patient. Ordinary skilled physicians can easily determine and prescribe an effective dosage (pharmaceutically effective amount) for desired treatment or prevention. According to a preferred embodiment of the present invention, the daily dose of the pharmaceutical composition of the present invention is about 0.0001 to about 100 mg/kg.

[0106] As used herein, the term pharmaceutically effective amount means an amount sufficient to prevent or treat the disease.

[0107] As used herein, the term prevention refers to any action that suppresses or delays the onset of a disease by administration of the pharmaceutical composition according to the present invention. As used herein, the term treatment refers to any action that reduces, inhibits, ameliorates or removes disease conditions.

[0108] The pharmaceutical composition of the present invention is formulated into a unit dose form or packaged into a multiple dose container using a pharmaceutically acceptable carrier and/or excipient in accordance with a method that can be easily performed by those skilled in the art. The formulation may be prepared in a variety of forms, such as an oral drug or injection, may be in the form of a solution, suspension or emulsion in an oil or aqueous medium, or in the form of an extract, a powder, a suppository, a powder, a granule, a tablet or a capsule, and may further contain a dispersant or stabilizer.

[0109] In another aspect, the present invention is directed to a method for preventing or treating bacterial infection, including administering to a subject an antibacterial composition containing the protein complex of the present invention described above.

[0110] As used herein, the term bacterial infection refers to a disease caused by bacterial infection. Examples of the bacterial infection include tuberculosis, pneumonia, food poisoning, sepsis, toxic shock syndrome, scarlet fever, diphtheria, brucellosis, listeriosis, typhoid fever, paratyphoid fever, cholera, botulism, tetanus, leprosy, leptospirosis, and the like, caused by the pathogens describe above, but are not limited thereto.

[0111] As used herein, the term administration or administering means directly administering a therapeutically or prophylactically effective amount of the composition of the present invention to a subject suffering from, or likely to suffer from, the disease of interest, so that the same amount accumulates in the body of the subject.

[0112] As used herein, the term therapeutically effective amount refers to the content of the composition sufficient to impart a therapeutic or prophylactic effect to the subject to whom the composition is administered, and is meant to include a prophylactically effective amount.

[0113] In addition, as used herein, the term subject refers to mammals including humans, mice, rats, guinea pigs, dogs, cats, horses, cows, pigs, monkeys, chimpanzees, baboons, and rhesus monkeys. Most specifically, the subject of the present invention is a human.

[0114] The method for preventing or treating bacterial infection of the present invention includes administering a pharmaceutical composition, which is an aspect of the present invention, and thus duplicate description is omitted to avoid excessive redundancy in the specification.

[0115] In another aspect, the present invention is directed to a feed additive containing the protein complex described above.

[0116] The feed additive may be in a liquid or dry form, for example, in a dried powder.

[0117] In addition, the feed additive may further contain ordinary additives that can increase the preservability of the feed in addition to the antibiotic.

[0118] Here, the feed additives include, but are not limited to, commercially available feed, grains, roots, fruits, food processing by-products, algae, fibers, pharmaceutical by-products, oils and fats, starches, cucurbits, grain by-products, proteins, inorganics, oils and fats, minerals, single-cell proteins, zooplankton, leftover food, and the like.

[0119] In another aspect, the present invention is directed to a food additive or drinking water additive containing the protein complex as an active ingredient. By mixing and supplying the protein complex with drinking water, the number of strains in drinking water can be reduced.

[0120] The protein complex of the present invention functions to deliver endolysin into the target strain using the botulinum toxin translocation domain and thus has lytic activity not only against Gram-positive bacteria but also against Gram-negative bacteria, which endolysin has difficulty acting upon, based on this function. Further, the usability of the protein delivery system can be improved using a receptor-binding protein.

[0121] The antibacterial activity of the protein complex of the present invention is based on the protein delivery system of the botulinum toxin translocation domain, and the endolysin and receptor-binding protein may be selected in accordance with the target strain, and exhibits antibacterial activity, regardless of the type of endolysin and receptor-binding protein.

[0122] Furthermore, when producing a protein complex by reacting (protein trans-splicing) a protein fragment containing a botulinum toxin translocation domain with a protein fragment containing endolysin, than when producing a full-length protein complex at once, the protein complex is not easily denatured during the preparation process and is not vulnerable to chemical stress, and the preparation efficiency thereof is improved.

[0123] In another aspect, the present invention is directed to a method for screening an antibacterial protein complex including reacting the protein complex with a target strain, and determining whether or not the protein complex exhibits antibacterial activity against the target strain.

[0124] Through the screening method, by reacting the protein complex containing receptor-binding protein candidates and endolysin candidates with the target strain, and determining whether or not the candidates exhibit antibacterial activity against the target strain can be determined, whether or not the candidates can be used as receptor-binding proteins and endolysin can be determined.

[0125] The method for determining whether or not the candidate exhibits the antibacterial activity is not particularly limited and a known method may be used singly or in combination. According to an embodiment of the present invention, the method may be performed through a spotting assay.

[0126] Hereinafter, the present invention will be described in more detail with reference to the following examples. It will be obvious to those skilled in the art that these examples are provided only for better understanding of the present invention and thus should not be construed as limiting the scope of the present invention based on the subject matter of the present invention.

[0127] Throughout this specification, percentage (%) used to indicate a concentration of a specific substance means (weight/weight) % for solid/solid, (weight/volume) % for solid/liquid, and (volume/volume) % for liquid/liquid, unless mentioned otherwise.

[0128] <Botulinum Toxin Translocation Domain, Endolysin, Receptor-Binding Protein, Intein, SpyTag/Spycatcher for Production of Translysin (Protein Complex)>

[0129] Botulinum toxin translocation domain (Table 1), endolysin (Table 2) for preparation of translysin, receptor-binding protein (Table 3), intein (Table 4), and SpyTag/Spycatcher (Table 5) are listed as follows.

TABLE-US-00001 TABLE 1 Botulinum toxin translocation domain (H.sub.N) NCBI Predicted Size Accession Name function (a.a) origin # BoNT A2 Translocation 422 Clostridium Q45894 Translocation domain botulinum (449-870 domain strain region) Kyoto/Type A2 BoNT C1 Translocation 416 Clostridium P18640 Translocation domain botulinum C (450-865 domain bacteriophage region) BoNT E1 Translocation 397 Clostridium Q00496 Translocation domain botulinum (423-819 domain region)

TABLE-US-00002 TABLE 2 Endolysin for production of translysin Predicted Size NCBI Name functions (a.a) Origin Accession # lys L-alanyl-D- 137 Escherichia YP_006868 glutamate virus T5 endopeptidase (M15) LysPA26 Muramidase 145 Pseudomonas KY615005 (GH24) phage JD010 PB1_gp48 Chitinase 220 Pseudomonas NC_011810 (GH19) phage PB1 LysAB2_P3 Chitinase 185 Acinetobacter HM755898 (GH19) phage phiAB2 PlyF307 Muramidase 146 Acinetobacter KJ740396 (GH24) phage RL-2015 AcLys Muramidase 184 Acinetobacter WP_000208716 (GH24) baumannii AB5075 prophage PlyPA03 Muramidase 144 Pseudomonas WP_070344501 (GH24) aeruginosa prophage PlyPA91 Muramidase 154 Pseudomonas CRR10611 (GH24) aeruginosa prophage Abtn-4 Chitinase 185 Acinetobacter AVP40474 (GH19) phage VB_AbaP_D2 WCHABP1_gp01 N-acetylmuramidase 171 Acinetobacter AST13128 (GH108) phage WCHABP1 WCHABP12_gp19 Chitinase 202 Acinetobacter ARB06760 (GH19) phage WCHABP12 gh-1p12 N- 146 Pseudomonas NP_813758 acetylmuramoyl- phage gh-1 L- alanine amidase B3ORF25 Membrane-bound 264 Pseudomonas YP_164061 lytic murein phage B3 transglycosylase F phi-13Sp4 P5 muramidase 245 Pseudomonas NP_690810 phage phi13 phi-6S_4 Peptidase_U40 220 Pseudomonas NP_620343 phage phi6 KP27_166 L-alanyl-D- 131 Klebsiella AEX26632 glutamate phage endopeptidase VB_KpnM_KP27 KP13_gp066 Muramidase 160 Klebsiella AZF89867 (GH24) phage VB_KpnS_Kp13 BI057_gp221 T4-like 164 Shigella phage YP_009279119 lysozyme SHFML-26 LPSE_00024 Soluble Lytic 162 Salmonella APU02985 Transglycosylases phage LPSE1 STP4a_120 Soluble Lytic 166 Salmonella AHJ86974 Transglycosylases phage STP4-a Lys68 Soluble Lytic 162 Salmonella AHY18890 Transglycosylases phage phi68 SPN1S_0028 Chitinase 209 Salmonella YP_005098003 (GH19) phage SPN1S P22gp66 Lysozyme 146 Salmonella NP_059622 virus P22

TABLE-US-00003 TABLE 3 Receptor-binding protein (RBP) Predicted Size NCBI Name functions (a.a) origin Accession # PRD1_04 Adsorption 591 Enterobacteria NC_001421 protein phage PRD1 P1301_0153 Receptor- 593 Bacteriophage ASU02516 binding T5-like protein chee130_1 P24_0149 Receptor- 585 Bacteriophage NC_047885 binding T5-like chee24 protein Pb5 Receptor- 640 Escherichia NC_005859 binding virus T5 tail protein AbTJ_gp52 Tail fiber 202 Acinetobacter QAU04145 protein phage AbTJ AbTJ_gp53 Tail fiber 699 Acinetobacter QAU04146 protein phage AbTJ phiAB6_gp40 Tail fiber 699 Acinetobacter ALA12264 phage phiAB6 S Tail fiber 504 Escherichia NC_000929 protein phage Mu A318_gp060 Receptor- 585 Escherichia phage NC_017969 binding vB_EcoS_AKFV33 tail protein rv5_gp030 Tail fiber 347 Escherichia YP_002003532 protein phage rV5 rv5_gp033 Putative 346 Escherichia YP_002003535 tail fiber phage rV5 protein PaoP5_075 Structural 243 Pseudomonas YP_009224766 protein phage PaoP5 BH773_gp153 Putative 670 Pseudomonas YP_009273830 tail fiber phage K5 protein AU075_gp145 Putative 499 Pseudomonas YP_009186965 tail fiber phage C11 protein CPT_Sugarland_191 Receptor- 658 Klebsiella phage ATW62004 binding Sugarland protein JIPhKp127_0170 Receptor- 658 Klebsiella phage QFR57578 binding JIPh_Kp127 protein AmPhEK80_0178 Receptor- 658 Klebsiella phage QFR57428 binding AmPh_EK80 protein P22_gp19 Tail spike 667 Salmonella phage NC_002371 protein P22 DET7_207 Tail spike 708 Salmonella phage YP_009140379 protein Det7 HWD08_gp154 Receptor- 585 Salmonella phage YP_009856550 binding L6jm tail protein BI021_gp088 Receptor- 595 Salmonella phage YP_009283429 binding NR01 protein HWD21_gp023 Receptor- 640 Salmonella phage YP_009857757 binding oldekolle tail protein HWC41_gp146 Receptor- 593 Salmonella phage YP_009848613 binding SE24 protein HOS12_gp017 Receptor- 585 Salmonella phage YP_009792475 binding SP01 protein HOU44_gp075 Receptor- 593 Salmonella phage YP_009815133 binding STG2 protein I133_gp019 Receptor 249 Salmonella phage YP_007501289 recognition vB_SenM-S16 protein HWC50_gp066 Receptor- 585 Salmonella virus YP_009849685 binding VSe12 tail protein HOS34_gp106 Receptor- 585 Shigella phage YP_009794581 binding SSP1 tail protein

TABLE-US-00004 TABLE4 Intein SEQ ID Name Domain Sequence NO: Remarks Gp41.1 Int-N CLDLKTQVQTPQGMKEISNIQVGDLVLSNTGYNEVL 1 NVFPKSKKKSYKITLEDGKEIICSEEHLFPTQTGEM NISGGLKEGMCLYVKE Int-C MMLKKILKIEELDERELIDIEVSGNHLFYANDILTH 2 N Cfa Int-N CLSYDTEILTVEYGFLPIGKIVEERIECTVYTVDKN 3 GFVYTQPIAQWHNRGEQEVFEYCLEDGSIIRATKDH KFMTTDGQMLPIDEIFERGLDLKQVDGLP Int-C MVKIISRKSLGTQNVYDIGVEKDHNFLLKNGLVASN 4 NRDJ-1 Int-N CLVGSSEIITRNYGKTTIKEVVEIFDNDKNIQVLAF 5 NTHTDNIEWAPIKAAQLTRPNAELVELEIDTLHGVK TIRCTPDHPVYTKNRGYVRADELTDDDELVVA Int-C MIEAKTYIGKLKSRKIVSNEDTYDIQTSTHNFFAND 6 ILVHN IMPDH-1 Int-N CFVPGTLVNTENGLKKIEEIKVGDKVFSHTGKLQEV 7 VDTLIFDRDEEIISINGIDCTKNHEFYVIDKENANR VNEDIHLFARWVVHAEELDMKKHLLIELE Int-C MKFKLKEITSIETKHYKGKVHDLTVNQDHSYNVRGT 8 VVHN Npu Int-N CLSYETEILTVEYGLLPIGKIVEKRIECTVYSVDNN 9 DnaE GNIYTQPVAQWHDRGEQEVFEYCLEDGSLIRATKDH KMTVDGQMLPIDEIFERELDLMRDNLPN Int-C MIKIATRKYLGKQNVYDIGVERDHNFALKNGFIASN 10 Ssp Int-N CLSFGTEILTVEYGPLPIGKIVSEEINCSVYSVDPE 11 DnaE GRVYTQAIAQWHDRGEQEVLEYELEDGSVIRATSDH RFLTTDYQLLAIEEIFARQLDLLTLENIKQTEEALD NHRLPFPLLDAGTIK Int-C MVKVIGRRSLGVQRIFDIGLPQDHNFLLANGAIAAN 12 Rma Int-N CLAGDTLITLADGRRVPIRELVSQQNFSVWALNPQT 13 DnaB YRLARVSRARVSRAFCTGIKPVYRLTTRLGRSIRAT ANHRFLTQGWKRVDELQPGDYLALPRRIPTASTPTL TEAELALLGHLIGD Int-C MWDPIVSIEPDGVEEVFDLTVPGPHNFVADNIIAGN 14 S Ppu Int-N CISKFSHIMWSHVSKPLFNFSIKKSHMHNGNKNIYQ 15 DnaB LLDQGEAFISRQDKKTTYKIRTNSEKYLELTSNHKI LTLRGWQRCDQLLCNDMITTQIGFELSRKKKYLLNC IPFSLCNFET Int-C MLANINISNFQNVEDFAANPIPNFIANNIIVHNS 16 Gp41.8 Int-N CLSLDTMVVINGKAIEIRDVKVGDWLESECGPVQVT 17 EVLPIIKQPVFEIVLKSGKKIRVSANHKFPTKDGLK TINSGLKVGDFLRSRA Int-C MCEIFENEIDWDEIASIEYVGVEETIDINVINDRLF 18 FANGILTHN NrdA-2 Int-N CLTGDAKIDVLIDNIPISQISLEEVVNLFNEGKEYV 19 LSYNIDTKEVEYKEISDAGLISESAEVLEIIDEETG QKIVCTPDHKVYTLNRGYVSAKDLKEDDELVES Int-C MGLKIIKRESKEPVFDITKVKDNSNFFANNILVHN 20

TABLE-US-00005 TABLE5 SpyTag&Spycatcher SEQID Name Domain Sequence NO: Remarks Spy001 Catcher GAMVDTLSGLSSEQGQSGDMTIEEDSATHIKF 32 SKRDEDGKELAGATMELRDSSGKTISTWISDG QVKDFYLYPGKYTFVETAAPDGYEVATAITFT VNEQGQVTVNGKATKGDAHI Tag AHIVMVDAYKPTK 33 Spy002 Catcher AMVTTLSGLSGEQGPSGDMTTEEDSATHIKFS 34 KRDEDGRELAGATMELRDSSGKTISTWISDGH VKDFYLYPGKYTFVETAAPDGYEVATAITFTV NEQGQVTVNGEATKGDAHTGSSGS Tag VPTIVMVDAYKRYK 35 Spy003 Catcher VTTLSGLSGEQGPSGDMTTEEDSATHIKFSKR 36 DEDGRELAGATMELRDSSGKTISTWISDGHVK DFYLYPGKYTFVETAAPDGYEVATPIEFTVNE DGQVTVDGEATEGDAHT Tag RGVPHIVMVDAYKRYK 37

[0130] However, the contents described in Tables 1 to 5 are provided for illustrating the present invention in more detail and Tables 1 to 5 should not be construed as limiting the scope of the present invention.

Example 1: Verification of Intracellular Expression and Lytic Effect of Full-Length Translysin

[0131] To express full-length translysin (endolysin-H.sub.N-RBP) in the expression host, E. coli shuffle T7, a plasmid encoding the translysin was designed. The protein complex was designed to have endolysin (T5 lys) and RBP (Pb5) bound to the amino and carboxyl ends of the botulinum toxin H.sub.N domain, respectively, and was inserted into a pET vector to produce a plasmid (FIG. 1). The sequence of the full-length translysin inserted into the vector is shown in SEQ ID NO: 21. The plasmid was inserted into an E. coli host at 42? C., cultured on LB (Luria-Bertani) agar medium supplemented with kanamycin at a concentration of 50 ?g/mL and a transformed E. coli strain was selected.

[0132] The selected transformed strain was inoculated into LB culture medium and sub-cultured. 1 mM IPTG (isopropyl ?-D-1-thiogalactopyranoside) was added to the cultured solution, followed by incubation at 37? C. for 4 hours to induce expression of translysin, which was then identified by SDS gel electrolysis (FIG. 2). As control groups, a transformed strain of a plasmid encoding an endolysin fragment or innolysin (T5 lys-linker-Pb5) and a wild-type strain were used, and the expression of innolysin was identified by SDS gel electrophoresis (FIG. 3). The sequence of innolysin is shown in SEQ ID NO: 22. The activity of translysin was predicted by measuring the growth of the strain based on the turbidity of the culture medium after expression. It was predicted that, when the expressed protein complex passed through the cell membrane and lysed the peptidoglycan of the cell wall, the strain died and turbidity decreased.

[0133] The result of expression showed that the strain expressing the endolysin fragment and innolysin did not exhibit a significant difference from the growth pattern of the wild-type strain, but when the translysin of the present invention was expressed, growth was significantly reduced, which indicates that membrane transfer occurred effectively (FIGS. 4 and 5).

Example 2: Protein Trans-Splicing of Protein Fragment by Intein

[0134] During the expression process, the full-length translysin expressed in Example 1 has problems in that 1) it has difficulty in reaching a sufficient cell concentration because the expression host is lysed, 2) it is readily denatured and is thus expressed at a low amount in a soluble form because the folding of the expression product of about 180 kDa is not smooth, and 3) it is vulnerable to physical and chemical stress during separation and purification because the size of the expression product reaches about 180 kDa. Therefore, in order to overcome these problems, the present invention adopts a method of expressing and purifying endolysin, iLCH.sub.N (inactivated botulinum toxin light chain+botulinum toxin translocation domain), and RBP as respective fragments linked to intein, and linking the fragments in vitro.

[0135] Gp41.1 intein and Cfa intein were selected from Table 4 in consideration of the linking conditions and reaction rates of inteins, and applied to endolysin-iLCH.sub.N and iLCH.sub.N-RBP binding, respectively. At this time, LysPA26 and PB1_gp48 in Table 2 were selected as endolysins, and PRD1_04 in Table 3 was selected as RBP.

[0136] The method for producing protein fragments is the same as in Example 1 and the sequences used to produce protein fragments are as follows:

TABLE-US-00006 LysPA26-Gp41.1N:SEQIDNO:23; PB1_gp48-Gp41.1N:SEQIDNO:24; Gp41.1C-iLCH.sub.N-CfaN:SEQIDNO:25; and CfaC-PRD1_04:SEQIDNO:26.

[0137] As a result, four protein fragments (LysPA26-Gp41.1N, 27.5 kDa; PB1_gp48-Gp41.1N, 35.3 kDa; Gp41.1C-iLCH.sub.N-CfaN, 117.2 kDa; CfaC-PRD1_04, 69.3 kDa) were expressed and purified. A protein trans-splicing reaction was performed (FIG. 6(A)).

[0138] First, to determine the trans-splicing effects of Gp41.1 intein and Cfa intein, the fragments were mixed at a molar ratio of 1:1 and the reaction was performed. As a result, 128.7 kDa (LysPA26-iLCH.sub.N-CfaN), 136.5 kDa (PB1_gp48-iLCH.sub.N-CfaN), and 168.9 kDa (gp41.1C-LCH.sub.N-PRD1_04) reaction products were obtained in buffer solution and saturated after 30 minutes (FIGS. 7 to 9). The result of the reaction performed by mixing the fragments at a molar ratio of 1:1:1 showed that the final product of 189.1 kDa, and the intermediate products of 136.5 kDa (PB1_gp48-iLCH.sub.N-CfaN) and 168.9 kDa (Gp41.1C-iLCH.sub.N-PRD1_04) were obtained in buffer solution regardless of the use of the reducing agent (FIG. 10).

Example 3: Conversion of Protein Fragments to Full-Length Proteins by Intein and SpyTag/SpyCatcher

[0139] In the full-length translysin produced in Example 2, the intein can be removed, but there was a problem of low trans-splicing efficiency of about 25%. Therefore, in order to overcome this problem, the present invention adopted a method of expressing and purifying endolysin, iLCH.sub.N, and RBP as respective fragments linked to intein and SpyTag/Spycatcher, and linking the fragments in vitro.

[0140] In consideration of the binding conditions and reaction rate of the intein and the mechanism of action of translysin, Gp41.1 intein was selected from Table 4 and applied to endolysin-iLCH.sub.N binding. In consideration of the reaction speed of the SpyTag/Spycatcher, the 3.sup.rd generation SpyTag/Spycatcher was selected from Table 5 and applied to iLCH.sub.N-RBP binding. At this time, LysPA26 was selected as the endolysin from Table 2 and PRD1_04 was selected as the RBP from Table 3.

[0141] The method for producing protein fragments is the same as in Example 1 and the sequences used to produce protein fragments are as follows:

TABLE-US-00007 LysPA26-Gp41.1N:SEQIDNO:23; Gp41.1C-iLCH.sub.N-Spy.sup.C003:SEQIDNO:42; and Spy.sup.T003-PRD1_04:SEQIDNO:43

[0142] As a result, three protein fragments (LysPA26-Gp41.1N, 27.5 kDa; Gp41.1C-iLCH.sub.N-Spy.sup.C003, 117.8 kDa; Spy.sup.T003-PRD1_04, 67.0 kDa) were expressed, purified and reacted into full-length translysin in vitro (FIG. 6(B)).

[0143] First, to determine the trans-splicing effect of Gp41.1 intein, the fragments were mixed at a molar ratio of 1:1 and the reaction was performed. The result showed that 129.1 kDa (LysPA26-iLCH.sub.N-Spy.sup.C003) was obtained in the buffer solution and saturated after 30 minutes (FIG. 11). In order to determine protein binding by SpyTag and Spycatcher, the fragments were mixed at a molar ratio of 1:1 and the reaction was performed. As a result, a reaction product of 184.8 kDa (gp41.1C-iLCH.sub.N-Spy-PRD1_04) was obtained in the buffer solution (FIG. 11). The result of the reaction performed by mixing respective fragments at a molar ratio of 1:1:1 showed that a final product of 196.1 kDa and an intermediate product of 129.1 kDa (Gp41.1C-iLCH.sub.N-Spy-PRD1_04) were produced in the buffer solution (FIG. 11).

Example 4: Verification of Lytic Activity of Full-Length Translysin and Protein Fragments

[0144] To determine the membrane transport and lytic activity of the full-length translysin produced in Examples 2 and 3, a spotting assay was performed on the target strain. The spotting assay is a method including overlaying a homogeneous mixture of 0.4% soft agar and the target strain on LB agar medium, drying the result, spotting the protein sample, culturing the sample, and determining death or growth inhibition patterns of strains on the lawn (FIG. 12).

[0145] Spotting assays were performed in two groups. First, to verify the lytic activity of endolysin, an experiment was conducted using dead cells in which the outer membrane of the Pseudomonas aeruginosa KACC 10186 strain was destroyed. For this purpose, the target strain was cultured until the exponential phase (OD.sub.600<2.0), sterilized at 121? C. using an autoclave, and then washed once with a buffer solution (50 mM Tris, 100 mM NaCl; pH 7, LysPA26/pH 6, PB1_gp48) to prepare a final 100-fold concentrated dead cell solution, diluted such that the turbidity of 0.4% soft agar was adjusted to OD.sub.600 of 10, and 5 mL of the dilution was placed on the LB agar medium in a 90? Petri dish. After the soft agar was dried, 10 ?L of each endolysin sample stock solution (10 ?g/?L) and the dilution (1 ?g/?L, 0.1 ?g/?L, 0.01 ?g/?L) were spotted, and a buffer solution was used as a negative control. The result of the test showed that both LysPA26 and PB1_gp48 endolysin fragments formed a lysis zone in the lawn, which indicates that the fragments exhibit lytic activity against the peptidoglycan of the target strain (FIGS. 13 and 14).

[0146] Then, to determine the membrane transport activity, an experiment was conducted by treating Pseudomonas putida KCTC 1643 viable cells with the protein sample under the same conditions. For this purpose, 100 ?L of live bacteria cultured overnight at 37? C. in LB culture medium until a stationary phase were homogeneously mixed with 5 mL of 0.4% LB soft agar and overlayed to create an environment that promotes the growth of live bacteria. After the soft agar was dried, 10 ?L of each of the stock solution (4 ?g/?L) and diluted solutions (0.4 ?g/?L, 0.04 ?g/?L) of translysin (PB1_gp48-iLCH.sub.N-PRD1_04, LysPA26-iLCH.sub.N-PRD1_04) and endolysin fragments (PB1_gp48-Gp41.1N, LysPA26-Gp41.1N) were spotted, and a buffer solution was used as a negative control. The result of the experiment showed that no lytic action occurred when treated with each endolysin fragment, whereas a lysis zone was formed when treated with full-length translysin, which indicates that the protein was effectively delivered into the outer membrane of the target strain and lysed the cell. (FIGS. 15 and 16).

[0147] The result was treated with translysin (PB1_gp48-iLCH.sub.N-PRD1_04, LysPA26-iLCH.sub.N-PRD1_04) and endolysin fragments (PB1_gp48-Gp41.1N, LysPA26-Gp41.1N) assembled through SpyTag and Spycatcher, and innolysin (LysPA26-iLCH N-PRD1_04, PB1_gp48-iLCH N-PRD1_04) at 3.6 ?M and 360 nM, respectively, under the same conditions. The result of the experiment showed that lytic activity did not occur when treated with each endolysin fragment, whereas when treated with full-length translysin and innolysin, a lytic zone was formed. The full-length translysin exhibited the effect at both 3.6 ?M and 360 nM, whereas innolysin exhibited the effect at 3.6 ?M (FIGS. 17 and 18).

Example 5: Visualization of Lytic Activity of Translysin

[0148] Transmission electron microscopy (TEM) was performed to visually detect the lytic activity of translysin verified in Example 4 (FIG. 19). For this purpose, the target strain P. putida KCTC 1643 was inoculated into the LB culture at a turbidity of OD.sub.600=0.1, cultured at 37? C. for 2 hours until the early exponential phase (OD.sub.600=1.0), and washed twice with a buffered saline solution to prepare live bacteria. Then, about 1 mL of the live bacteria solution was mixed with 370 nM translysin (PB1_gp48-iLCH.sub.N-PRD1_04, LysPA26-iLCH.sub.N-PRD1_04), cultured at 25? C., and 10 ?L of the mixture was collected at a predetermined time point, fixed on a gold grid, and then stained with uranyl acetate for 10 seconds to prepare a TEM sample. A negative control sample was prepared in the same manner as above by treating a strain with each endolysin fragment (PB1_gp48-Gp41.1N, LysPA26-Gp41.1N) at a concentration of about 370 nM, or was prepared in the same manner as above using a strain without any treatment. As a result of analysis using an energy-filtering transmission electron microscope (Energy-Filtering TEM, 120 kv) (Carl Zeiss, Libra 120), no external damage was observed in the negative control, whereas the cell wall of the experimental group treated with translysin was damaged over time and the strain died (FIG. 19).

Example 6: Quantification of Lytic Activity of Translysin

[0149] CFU (Colony Forming Unit) reduction assay was performed to numerically determine the lytic activity of translysin verified in Example 4. For this purpose, the target strain P. putida KCTC 1643 was inoculated into LB culture medium at a turbidity of OD.sub.600=0.1, cultured at 37? C. for 1.5 hours until the early exponential phase (OD.sub.600=0.6), washed three times with a 20 mM HEPES-NaOH (pH=7.4) solution, diluted 100 times and prepared as live bacteria. Then, 100 uL of translysin (LysPA26-iLCH.sub.N-PRD1_04) or innolysin (LysPA26-PRD1) was mixed at a concentration of 30 ?M with 100 ?L of the live bacteria solution and reacted at 37? C. for 1 hour. As a negative control, a sample was prepared in the same manner as above using 20 mM Hepes-NaOH. Then, the result was diluted with an appropriate dilution factor, spread on LB agar medium, and cultured O/N at 37? C. Antibacterial activity was determined based on the difference in mean logarithmic cell concentration of translysin- or innolysin-treated samples compared to the negative control. The result of the experiment showed that translysin exhibited about twice the lytic activity of innolysin (FIG. 20).

Example 7: Translysin Library-Based Antibacterial Substance Screening

[0150] A translysin screening method was designed to discover antibacterial substances against various strains using the protein delivery system of the present invention (FIG. 21). Specifically, the endolysins and RBPs in Tables 2 and 3 were combined to construct a translysin library, and viable cells of the target strain in Table 6 were homogeneously mixed with 0.4% LB soft agar to form a lawn. Then, novel antibacterial materials for each strain could be discovered by determining the lytic activity through spotting assay.

TABLE-US-00008 TABLE 6 Candidate bacteria Remarks Pseudomonas aeruginosa PAO1 Pseudomonas aeruginosa KACC 10186 Pseudomonas aeruginosa ATCC 15692 Pseudomonas aeruginosa ATCC 27853 Pseudomonas putida KCTC 1643 Escherichia coli BL21 Escherichia coli MG1655 Escherichia coli ATCC 43889 O157:H7, Stx2, hemolytic uremic syndrome Escherichia coli ATCC 43890 O157:H7, Stx1 Escherichia coli ATCC 43895 O157:H7, Stx1, Stx2, hemorrhagic colitis Escherichia coli ATCC 35150 O157:H7, hemorrhagic colitis Escherichia coli ATCC 25922 O6, clinical isolate Salmonella Typhimurium SL1344 Salmonella Typhimurium UK-1 Salmonella Typhimurium 14028s Salmonella Typhimurium LT2 Salmonella Typhimurium DT104 zoonotic pathogen, MDR Klebsiella pneumoniae subsp. pneumoniae ATCC 10031 Klebsiella pneumoniae KCTC 2242 Klebsiella pneumoniae ATCC 13883 Klebsiella pneumoniae Revco 41

[0151] In the present invention, P. putida KCTC 1643 strain was treated with six types of translysins (PB1_gp48-iLCH.sub.N-PRD1, PB1_gp48-iLCH.sub.N-chee24, LysPA26-iLCH.sub.N-PRD1, LysPA26-iLCH.sub.N-chee24, T5Lys-iLCH.sub.N-PRD1, T5Lys-iLCH.sub.N-chee24), and the combinations exhibiting lytic activity were screened. The result showed that all translysins containing PRD1_04 RBP exhibited lytic activity against the target strain (FIG. 22).

[0152] The sequence additionally used to prepare the translysin is as follows:

TABLE-US-00009 T5Lys-Gp41.1N:SEQIDNO:27; and CfaC-T5likechee24:SEQIDNO:28.

[0153] The translysin of the present invention is a protein complex in which an antibacterial protein endolysin derived from a bacteriophage and a receptor-binding protein (RBP) are linked to the translocation domain H.sub.N of botulinum toxin, and was designed that RBP was disposed at the carboxyl terminus (C-terminal) and endolysin was disposed at the amino terminus (N-terminal) (FIG. 23) such that H.sub.N was disposed between the RBP and the endolysin.

[0154] Based on this design, when translysin interacts with the target strain, the RBP at the carboxyl-terminus recognizes and attaches to the receptor located on the outer membrane, then H.sub.N is incorporated into the cell membrane, and the endolysin at the amino terminal is close to peptidoglycan to induce lytic action and to kill cells (FIG. 24).

[0155] The translysin of the present invention was predicted to reach about 180 kDa in size. Considering the possibility of problems with yield and purity during the process of expressing and purifying translysin, a method of expressing the full-length protein and a method of separately expressing split protein fragments and then linking the fragments in vitro were performed respectively and compared. The result showed that the method of separately expressing the split protein fragments and then linking the same compensated for the drawbacks of the conventional method and was able to produce an intact full-length protein.

[0156] In the present invention, intein and SpyTag/Spycatcher are introduced as a means of binding respective fragments of endolysin, translocation domain, and RBP, and protein fragments are assembled into full-length proteins through protein trans-splicing and bioconjugation (FIGS. 25 and 26). In addition, novel antibacterial substances can be screened by combining various endolysins and RBPs using inteins and SpyTags/Spycatchers to construct a translysin library, and detecting the lytic activity of each translysin.