The present invention provides a method for rapid, highly specific and sensitive detection and quantification of a virus by observing viral substrate binding to its host receptor protein. The invention also provides a method for rapid, highly specific and sensitive detection and quantification of a virus in an individual suspected of being infected with a virus. The invention further provides a test kit for rapid, highly specific and sensitive point-of-care detection of a virus in an individual. The viruses and their host receptor proteins that can rapidly be detected include SARS-CoV-2 and its host receptor protein ACE2. The surprisingly rapid, specific, sensitive method and kit of the invention provide a point-of care test capable of diagnosing individuals suffering from COVID-19 by observation of a color change in the assay, which color change occurs in about five minutes, and which test can be completed by a user in about 60 minutes.

The present invention concerns an in vitro screening assay for identification of modulators of tubulin carboxypeptidase (TCPase) activity comprising the steps of: (i) Contacting (a) a substrate of TCPase enzyme comprising an amino acids sequence having at least the last 4 amino acids residues of the C-terminal sequence of an α-tubulin and/or a Microtubule Associated Protein (MAP) and, as ultimate C-terminal amino acid residue, an aromatic amino acid residue, preferably a tyrosine (Y), and b) an isolated or recombinant TCPase enzyme; in the presence or absence (control) of the modulator compound to be tested, and under conditions for substrate cleavage, preferably detyrosination, and/or liberation of a C-terminal free aromatic amino acid residue, preferably a C-terminal free tyrosine; (ii) Using reagents for detecting and measuring the signal related to substrate cleavage, preferably detyrosination, and/or liberation of the C-terminal free aromatic amino acid residue, preferably the C-terminal free tyrosine; (iii) Measuring and comparing the level of substrate cleavage, preferably detyrosination and/or the level of the C-terminal free aromatic amino acid residue, preferably the C-terminal free tyrosine in presence and in absence (control) of the compound to be tested, and (iv) Selecting the modulators of TCPase for which the level of substrate cleavage, preferably detyrosination or liberation of the C-terminal aromatic amino acid residue, preferably C-terminal free tyrosine is increased in the presence of the compound to be tested (activators of TCPase) or decreased in the presence of the compound to be tested (inhibitors of TCPase). The present invention also concerns kits for performing such in vitro screening assay.

An agent uses at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof as an active ingredient. The present invention also provides an agent for improving a neuropsychologic function, which contains at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof as an active ingredient. The present invention also provides an agent for changing expression of a transporter such as SLC23A2, which contains at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof, and an agent for controlling blood concentration of a cytokine such as IP-10, which contains at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof, as well as an expression analysis method for detecting improvement or degradation of a neuropsychologic function, and a kit for detecting improvement or degradation of a neuropsychologic function.

An anti-aging agent derived from a natural product is provided. The agent uses at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof as an active ingredient. The present invention also provides an agent for improving a neuropsychologic function, which contains at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof as an active ingredient. The present invention also provides an agent for changing expression of a transporter such as SLC23A2, which contains at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof, and an agent for controlling blood concentration of a cytokine such as IP-10, which contains at least one selected from the group consisting of an imidazole dipeptide and a metabolite thereof, as well as an expression analysis method for detecting improvement or degradation of a neuropsychologic function, and a kit for detecting improvement or degradation of a neuropsychologic function.

An application of a biomarker in preparing metabolic dysfunction-associated steatotic liver disease classification products is provided. The biomarker is any one or more of the following: a combination of liver protein biomarkers, a combination of serum protein biomarkers, a combination of serum lipid biomarkers, a combination of serum metabolite biomarkers, a combination of serum protein, lipid and metabolite biomarkers, a combination of urine protein biomarkers, a combination of urine metabolite biomarkers, and a combination of urine protein and metabolite biomarkers; and the metabolic dysfunction-associated steatotic liver disease is divided into a metabolically active type, a high-risk type of cirrhosis and a high-risk type of hepatocellular carcinoma. The combinations of biomarkers provided by the present disclosure have a good effect on the diagnosis of three MASLD molecular subtypes, which provides technical support for the classification and diagnosis of MASLD.