The present disclosure concerns a recombinant yeast host cell exhibiting higher stability and, in some embodiments, higher fermentation performance. The recombinant yeast host cell stability has a limited ability to express an hydrolase during its propagation phase. In return, this limits the cleavage of a yeast cellular component during or after propagation which may be detrimental to the stability and/or fermentation performances. The recombinant yeast host cell expresses a heterologous hydrolase under the control of a heterologous promoter (for limiting the expression of the heterologous hydrolase during propagation and favoring the expression of the heterologous hydrolase during fermentation).

The present disclosure relates to recombinant fusion proteins comprising an extracellular domain of the human angiotensin-converting enzyme 2 (ACE2), optionally having altered amino acid residues that result in increased binding affinity for the S1 spike protein of SARS-CoV-2, linked to a human immunoglobulin Fc region, that can extend the protein half-life (T.sub.1/2) and/or the duration of action as a decoy receptor, and compositions and methods of use of these fusion proteins.

Methods and compositions relating to an engineered peptide capable of binding to a biological molecule for viral inhibition. The engineered peptide is computationally-derived from soluble angiotensin-converting enzyme 2 (sACE2), a known receptor for viral spike proteins. The engineered peptide is optimized for minimal size and off-target effects. The engineered sACE2 peptide variants are a suitable targeting domain for fusion proteins of various effects.

Provided herein, in some aspects, are polypeptide monomers comprising an angiotensin-converting enzyme 2 (ACE2) ectodomain and an oligomerization domain. Also provided herein are oligomeric complexes comprising ACE2 monomers. Methods of using such to monomers and oligomeric complexes for the diagnosis, prevention, and treatment of viral infections such as the coronavirus are also provided.

The present invention relates to a method for producing a protein hydrolysate using a polypeptide having endopeptidase activity and a polypeptide having carboxypeptidase activity and the use of these enzymes for hydrolysing a protein substrate. In addition, the present invention relates to polypeptides having carboxypeptidase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Provided herein are modified cleavases for removing amino acids from peptides, polypeptides, and proteins. Also provided are methods of using the modified cleavases for treating polypeptides, and kits comprising the modified cleavase. In some embodiments, the methods and the kits also include other components for macromolecule sequencing and/or analysis.

A method for inhibiting infection of SARS-CoV-2 in a subject is provided, comprising administering an effective amount of plant extract, wherein the plant extract comprises an alcohol extract of the herbal of Menispermaceae, wherein the herbal of Menispermaceae is Stephania cepharantha or Stephania tetrandra.

The present disclosure relates to fusion protein compositions and methods of reducing and treating viral infections. The fusion proteins include a polypeptide comprising a b1 domain, or a derivative or fragment thereof, of a neuropilin; an ACE2 domain, or a derivative or a fragment thereof, of an angiotensin converting enzyme 2; and or an immunoglobulin domain. Both the b1 and ACE2 domains are capable of binding to a coat protein of a virus selected from the group consisting of herpesviridae, papillomaviridae, coronaviridae, flaviviridae, togaviridae, bomaviridae, bunyaviridae, filoviridae, orthomyxoviridae, paramyxoviridae, pneumoviridae, and retro viridae. In some embodiments, the b1 domain, or a derivative or fragment thereof, and/or the (ACE2) domain, can be used to specifically bind S proteins of COVID-19 particles.

The present invention provides polypeptides with coronavirus neutralising capacity. It further provides nucleic acids, vectors, cells, pharmaceutical compositions and medical uses that exploit the polypeptides of the invention

The present invention relates to a bacterial host cell in which a first chromosomal gene encoding a first alanine racemase and a second chromosomal gene encoding a second alanine racemase have been inactivated. Said bacterial host cell comprises – either on a plasmid comprising at least one autonomous replication sequence or present as multiple copies in the chromosome – a gene expression cassette comprising a polynucleotide encoding at least one polypeptide of interest, operably linked to a promoter, and a polynucleotide encoding a third alanine racemase, operably linked to a promoter. The present invention further relates to a method for producing at least one polypeptide of interest based on cultivating the bacterial host cell of the present invention.