Biomaterial Database

Evidence for a common high affinity binding site on glutathione S-transferase B for lithocholic acid and bilirubin. 1984

Y Sugiyama, and A Stolz, and M Sugimoto, and N Kaplowitz

Binding of lithocholic acid, bilirubin, and gossypol to glutathione S-transferase B (ligandin or transferase YaYc) was compared using four methods. Tryptophan quenching revealed a single high affinity site for bilirubin and gossypol but could not be used for lithocholic acid. Both displacement of the fluorescent probe, 1-anilino-8-naphthalenesulfonate, and spectral changes induced by bilirubin binding demonstrated a common high affinity site for which all three ligands compete. Similar results were obtained by equilibrium dialysis. The dissociation constants for the binding of both bilirubin and lithocholic acid were comparable with the various methods (range 0.2-0.7 microM). Thus, lithocholic acid and bilirubin share a high affinity binding site on gluthathione S-transferase B that appears to be separate from the binding site for substrates.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D008095	Lithocholic Acid	A bile acid formed from chenodeoxycholate by bacterial action, usually conjugated with glycine or taurine. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as cholagogue and choleretic.	Lithocholate,Isolithocholic Acid,Acid, Isolithocholic,Acid, Lithocholic
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D011485	Protein Binding	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.	Plasma Protein Binding Capacity,Binding, Protein
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D005456	Fluorescent Dyes	Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.	Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D005982	Glutathione Transferase	A transferase that catalyzes the addition of aliphatic, aromatic, or heterocyclic FREE RADICALS as well as EPOXIDES and arene oxides to GLUTATHIONE. Addition takes place at the SULFUR. It also catalyzes the reduction of polyol nitrate by glutathione to polyol and nitrite.	Glutathione S-Alkyltransferase,Glutathione S-Aryltransferase,Glutathione S-Epoxidetransferase,Ligandins,S-Hydroxyalkyl Glutathione Lyase,Glutathione Organic Nitrate Ester Reductase,Glutathione S-Transferase,Glutathione S-Transferase 3,Glutathione S-Transferase A,Glutathione S-Transferase B,Glutathione S-Transferase C,Glutathione S-Transferase III,Glutathione S-Transferase P,Glutathione Transferase E,Glutathione Transferase mu,Glutathione Transferases,Heme Transfer Protein,Ligandin,Yb-Glutathione-S-Transferase,Glutathione Lyase, S-Hydroxyalkyl,Glutathione S Alkyltransferase,Glutathione S Aryltransferase,Glutathione S Epoxidetransferase,Glutathione S Transferase,Glutathione S Transferase 3,Glutathione S Transferase A,Glutathione S Transferase B,Glutathione S Transferase C,Glutathione S Transferase III,Glutathione S Transferase P,Lyase, S-Hydroxyalkyl Glutathione,P, Glutathione S-Transferase,Protein, Heme Transfer,S Hydroxyalkyl Glutathione Lyase,S-Alkyltransferase, Glutathione,S-Aryltransferase, Glutathione,S-Epoxidetransferase, Glutathione,S-Transferase 3, Glutathione,S-Transferase A, Glutathione,S-Transferase B, Glutathione,S-Transferase C, Glutathione,S-Transferase III, Glutathione,S-Transferase P, Glutathione,S-Transferase, Glutathione,Transfer Protein, Heme,Transferase E, Glutathione,Transferase mu, Glutathione,Transferase, Glutathione,Transferases, Glutathione
D000817	Anilino Naphthalenesulfonates	A class of organic compounds which contain an anilino (phenylamino) group linked to a salt or ester of naphthalenesulfonic acid. They are frequently used as fluorescent dyes and sulfhydryl reagents.	Naphthalenesulfonates, Anilino