An object of the present invention is to provide a pharmaceutical composition or food or drink composition comprising an active ingredient that suppresses functional expression of Oscar protein. Another object of the present invention is to provide a pharmaceutical composition or food composition for preventing or treating kidney disease. A further object of the present invention is to provide a pharmaceutical composition or food or drink composition that suppresses functional expression of Oscar in a living organism in order to suppress functional expression of FGF23. A still further object of the present invention is to provide a method for evaluating an effect, in the body, of an active ingredient that suppresses functional expression of Oscar protein. The above objects are achieved by at least one member selected from the group consisting of antagonists of the Oscar protein; genome editing systems that target Oscar gene; at least one RNA molecule selected from the group consisting of siRNA, shRNA, and miRNA that target Oscar mRNA, or vectors capable of expressing the RNA molecule; and antibodies that specifically bind to the Oscar protein and suppress function of the Oscar.

A method for determining the amount of one or more analytes in a sample by mass spectrometry is described. The one or more analytes are selected from the group consisting of alpha-hydroxybutyrate (2-HB), linoleoyl LPC (LGPC), oleic acid, 3-hydroxybutyrate (3-HB), 4-methyl-2-oxopentanoate (4-MOP), pantothenate, and serine. The method includes a) subjecting the sample to an ionization source under conditions suitable to produce one or more ions detectable by mass spectrometry from each of the one or more of the analytes, wherein the analytes are not derivatized prior to ionization; b) measuring, by tandem mass spectrometry, the amount of the one or more ions from each of the one or more analytes; and c) using the measured amount of the one or more ions to determine the amount of each of the one or more analytes in the sample.

A system and method for using new biomarkers to assess individual diseases is provided. In one embodiment of the present invention, absolute quantification of annotated metabolites by mass spectrometry is used to identify certain biomarkers and derivatives thereof (i.e., signatures), which are then used to screen for, diagnose, predict, prognose, and treat various diseases, including, but not limited to, breast cancer, ovarian cancer, colorectal cancer, pancreatic cancer, and acute graft-versus-host disease.

The purpose of the present invention is to provide: a method for predicting the prognosis for kidney disease for a subject on the basis of the amount of D- and L-amino acids, from a blood sample; and an analysis system that determines prognosis predictions. This purpose is achieved by using at least one amino acid to predict the prognosis for kidney disease, said amino acid being selected from the group consisting of D-serine, D-asparagine, D-proline, D-alanine, D-leucine, D-lysine, D-allo-isoleucine, L-glutamic acid, L-alanine, L-tryptophan, and L-asparagine.

The present invention relates to N-acyl amino acid products and their use in diagnosing and treating disease.

Scintillant-doped polystyrene core nanoparticles surrounded by a silica shell can be used to quantify low-energy radionuclides. The nanoparticles are recoverable and re-useable, which may reduce waste and allow for sample recovery. Unlike traditional liquid scintillation cocktail (LSC) formulations, the nanoparticles are made from non-toxic and non-volatile components, and can be used without the aid of surfactants, making them a possible alternative to LSC for reducing the environmental impact of studies that employ radioactive tracers. Recognition elements attached to the functionalized silica surfaces of the nanoparticles allow for separation-free scintillation proximity assay (SPA) applications in aqueous samples. Lipid membrane coatings deposited on the nanoparticle surface can significantly reduce the non-specific adsorption of proteins and other biomolecules, and allow for the incorporation of membrane proteins or other membrane associated binding molecules.

The present invention provides a mutated histidine decarboxylase suitable for a practical use. Specifically, the present invention provides a mutated histidine decarboxylase having at least one amino acid residue mutated as compared to a wild-type histidine decarboxylase, and having higher histidine decarboxylase activity and/or stability than the wild-type histidine decarboxylase, and also a use thereof. The mutated histidine decarboxylase has Motifs (1) to (6), and an amino acid residue in at least one motif thereof can be mutated. The mutated histidine decarboxylase can also have a mutation of at least one amino acid residue in an amino acid sequence designated by SEQ ID NO: 3 and in a homologous sequence thereto.

A peptide aptamer for specific recognition of arginine and its application are provided. The sequence of the peptide aptamer is shown in SEQ ID No. 1. The peptide aptamer is modified by a group that improves stability, or by a fluorescent group, an isotope and an electrochemical group that provide a detection signal, or by an affinity ligand and a mercapto. According to the computer-aided molecular docking simulation prediction, the peptide aptamer that can specifically bind to L-arginine is screened, which is verified by an isothermal titration calorimeter. The peptide aptamer has the advantages of good stability, strong binding ability, high specificity and low production cost.

Provided is an arginine fluorescent probe, comprising a polypeptide B that responds to arginine and a fluorescent protein A that expresses arginine; the fluorescent protein A is inserted into the polypeptide B, B is divided into an upper structural part and a lower structural part, B1 and B2, and a probe structure represented by the formula B1-A-B2 is formed; optimized mutants are likewise obtained by truncation and site-directed mutagenesis at different positions, and specific binding of the polypeptide B and arginine leads to a change in the fluorescence signal of the fluorescent protein A; and the polypeptide B is an arginine binding protein or a mutant thereof. The arginine fluorescent probe provided by the present invention has a relatively small protein molecular weight, is easy to express, experiences large dynamic changes in fluorescence, has good specificity, can be expressed, by means of genetic manipulation, in different subcellular organelles of cells, and can be used for the high-throughput, quantitative detection of arginine inside and outside of cells.

Disclosed is a tryptophan optical probe, a preparation method therefor and the use thereof. Disclosed is an optical probe, comprising a tryptophan-sensitive polypeptide or a functional variant thereof and an optically active polypeptide or a functional variant thereof, wherein the optically active polypeptide or the functional variant thereof is located in the sequence of the tryptophan-sensitive polypeptide or the functional variant thereof. Furthermore, disclosed are a method for preparing the above-mentioned probe and the use thereof in the detection of tryptophan.