The present invention relates to tetramolecular parallel G-quadruplex-forming oligonucleotides. If G-quadruplexes are of prime importance in biology, their use is hampered by the propensity of G4-prone DNA molecules, in particular G4-prone DNA molecules of long size, to adopt many different G4 topological conformations or other alternative foldings. By introducing a lipid modification at the end of the oligonucleotide, the inventors succeeded in obtaining long tetramolecular parallel G-quadruplexes (tpG4). The present invention thus concerns an oligonucleotide modified by substitution at the 5 or the 3 end by a lipid moiety, wherein said oligonucleotide comprises a nucleic acid sequence of at least 10 nucleotides, said nucleic acid sequence including a series of at least 4 consecutive guanine residues located in the middle of said sequence. A tetramolecular parallel G-quadruplex comprising 4 identical modified oligonucleotides as defined above, wherein each of the 4 consecutive guanine residues included in the middle of the nucleic acid sequence of each oligonucleotide respectively form G-quartets with the corresponding guanine residues of the other 3 oligonucleotides, said G-quartets being stabilized by - staking and Hoogsteen hydrogen bonding, is also contemplated. The modified oligonucleotides have preferably the general formula (I) or (II), wherein the oligonucleotides are modified by substitution at the 5 or the 3 end by a lipid moiety, and said oligonucleotides comprise a nucleic acid sequence of at least 10 nucleotides, said nucleic acid sequence including a series of at least 4 consecutive guanine residues located in the middle of said sequence.

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Provided is an aptamer including a polynucleotide of any of the following (a) to (c) and capable of binding to an HGF receptor to exhibit an activity of inhibiting the binding of HGF to the HGF receptor. (a) A polynucleotide consisting of a base sequence set forth in SEQ ID NO:1, (b) A polynucleotide consisting of a base sequence having the deletion, substitution, insertion and/or addition of one to several bases in the base sequence set forth in SEQ ID NO:1, and (c) A polynucleotide consisting of a base sequence having a sequence identity of 80% or more to the base sequence set forth in SEQ ID NO:1.

Disclosed is a complex tFNA-miR22 for treating optic nerve disease, which complex is composed of tetrahedral DNA and miR-22 according to a molar ratio of 1:(1-4). The tFNA-miR22 can effectively inhibit apoptosis of retinal ganglion cells and promote the release of a brain-derived neurotrophic factor (BDNF), thereby achieving a good protection effect for the retinal ganglion cells. The tFNA-miR22 is used for preparing optic nerve protection drugs, the treatment of neurodegenerative optic nerve diseases including glaucoma is facilitated, and the tFNA-miR22 has very good application prospects.

Compositions comprising optimized aptamers capable of specifically binding to a surface protein of Clostridium difficile spore are provided. A method for detecting, enriching, separating, and/or isolating Clostridium difficile spores is provided.

Systems and method for providing chaperone activity to a protein-containing compound is disclosed. The method includes selecting a nucleic acid based on one or more of the nucleic acid's particular properties and a specific sequence of the nucleic acid and applying the nucleic acid to a compound comprising one or more proteins to provide chaperone activity to the compound.

Quadruplex-forming guanine-rich nucleic acid sequences are useful in compositions and methods for inhibiting cellular growth and proliferation and inducing cell death. Compositions for treating a patient are provided, including (i) a safe and effective amount of a sequence having at least 80% nucleic acid identity with a sequence selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12 and combinations thereof, and (ii) a carrier, wherein the isolated oligonucleotide forms at least one quadruplex.

Materials and methods related to using short DNA aptamers to treat demyelinating diseases are provided herein.

Described herein are compositions that may be used to detect viral nucleic acid. For example, these compositions may comprise a DNA-nanostructure, a capture oligonucleotide and a protector oligonucleotide, wherein the components are designed based on a duo-toehold-mediated displacement reaction (duo-TMDR) strategy. In this strategy, a first TMDR can switch off a Foster resonance energy transfer (FRET) process and a second TMDR can release the target viral nucleic acid and amplify the signal. Methods of using such compositions are also provided herein.

Novel DNA molecule-based compositions and methods for delivery to target cells provide modulation of target G-quadruplex formation in the tyrosine hydroxylase (TH) promoter and allow for enhancement or repressing of specific G-quadruplexes that in turn regulate tyrosine hydroxylase transcription and catecholamine production, specifically dopamine. Use of the DNA-molecule-based compositions in treatment of neurological diseases and disorders is facilitated through a nanoparticle-based delivery system.

The present invention is intended to provide a novel fluorescence sensor for target analysis, a kit for target analysis, and a target analysis method using the same. The fluorescence sensor for target analysis according to the present invention includes a nucleic acid molecule that includes a G-quartet-forming nucleic acid region (D) that forms a G-quartet and a binding nucleic acid region (A) that binds to a target. In the absence of a target, formation of a G-quartet in the G-quartet-forming nucleic acid region (D) is inhibited. In the presence of a target, the target comes into contact with the binding nucleic acid region (A), the G-quartet is formed in the G-quartet-forming nucleic acid region (D) due to the contact, the G-quartet-forming region (D) and porphyrin forms a complex, and the complex generates fluorescence.