Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.

Biologically active molecules which are covalently bound to the enzymes or binding proteins normally acting on them. Binding occurs due to activation of the label by ultraviolet light. These labels are used primarily to identify binding sites on proteins.

Organic or inorganic compounds that contain the -N3 group.

Photochemistry is the study of chemical reactions induced by absorption of light, resulting in the promotion of electrons to higher energy levels and subsequent formation of radicals or excited molecules that can undergo various reaction pathways.

Chemical bond cleavage reactions resulting from absorption of radiant energy.

The sum of the weight of all the atoms in a molecule.

The rate dynamics in chemical or physical systems.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Cell surface proteins that bind cyclic AMP with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized cyclic AMP receptors are those of the slime mold Dictyostelium discoideum. The transcription regulator CYCLIC AMP RECEPTOR PROTEIN of prokaryotes is not included nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.

Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.

The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.

A large group of membrane transport proteins that shuttle MONOSACCHARIDES across CELL MEMBRANES.

A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.

Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

Transport proteins that carry specific substances in the blood or across cell membranes.

Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.

Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

Benzophenones are synthetic organic compounds characterized as aromatic ketones, often used in chemical synthesis for various applications including sunscreen formulations due to their UV-absorbing properties.

Diazonium compounds are organic derivatives containing the general formula R-N2+X-, where R represents an aryl or alkyl group, and X- is an anion such as bromide or chloride, formed by the reaction of amines with nitrous acid in an acidic medium.

Unsaturated azacyclopropane compounds that are three-membered heterocycles of a nitrogen and two carbon atoms.

Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)

Diazomethane is an extremely hazardous and unstable organic compound, (CH2)N=N=O, with a methane substituted diazo group, that is highly explosive when heated, shocked or contaminated, and used as a powerful methylating agent in chemical syntheses, but its production and handling require special expertise and equipment due to the high risks involved.

Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Unstable isotopes of phosphorus that decay or disintegrate emitting radiation. P atoms with atomic weights 28-34 except 31 are radioactive phosphorus isotopes.

Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.

Azo compounds are organic compounds characterized by the presence of one or more azo groups, -N=N-, linking two aromatic rings, which can impart various colors and are used in dyes, pharmaceuticals, and chemical research.

The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.

A benzodiazepine with pharmacologic actions similar to those of DIAZEPAM that can cause ANTEROGRADE AMNESIA. Some reports indicate that it is used as a date rape drug and suggest that it may precipitate violent behavior. The United States Government has banned the importation of this drug.

The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)

Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.

Pyridine moieties which are partially saturated by the addition of two hydrogen atoms in any position.

That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.

Uridine Diphosphate (UDP) sugars are nucleotide sugars that serve as essential glycosyl donors in the biosynthesis of various glycoconjugates, including proteoglycans and glycoproteins.