Biomaterial Database

Inactivation of dihydropteridine reductase (human brain) by platinum(II) complexes. 1987

W L Armarego, and A Ohnishi

Potassium tetrachloroplatinate (K2PtCl4) inactivates dihydropteridine reductase from human brain in a time-dependent and irreversible manner. The inactivation has been followed by measuring enzyme activity and fluorescence changes. The enzyme is completely protected from inactivation by NADH, the pterin cofactor [quinonoid 6-methyl-7,8-dihydro(6H)pterin] and dithiothreitol. Evidence is presented that K2PtCl4 reacts at the active site and that (a) thiol group(s) is involved in, or is masked by, this reaction. K2PtCl4 is a stronger inhibitor of human brain dihydropteridine reductase that cis- and trans-diaminodichloroplatinum, cis-dichloro[ethylenediamine]platinum and K4Fe(CN)6, whereas H2PtCl6 is considerably weaker and (Ph3P)3RhCl is inactive.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009247	NADH, NADPH Oxidoreductases	A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.	Oxidoreductases, NADH, NADPH,NADPH Oxidoreductases NADH,Oxidoreductases NADH, NADPH
D009944	Organoplatinum Compounds	Organic compounds which contain platinum as an integral part of the molecule.	Compounds, Organoplatinum
D010984	Platinum	A heavy, soft, whitish metal, resembling tin, with atomic number 78, atomic weight 195.084, symbol Pt. It is used in manufacturing equipment for laboratory and industrial use. It occurs as a black powder (platinum black) and as a spongy substance (spongy platinum) and may have been known in Pliny's time as "alutiae".	Platinum Black
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D002945	Cisplatin	An inorganic and water-soluble platinum complex. After undergoing hydrolysis, it reacts with DNA to produce both intra and interstrand crosslinks. These crosslinks appear to impair replication and transcription of DNA. The cytotoxicity of cisplatin correlates with cellular arrest in the G2 phase of the cell cycle.	Platinum Diamminodichloride,cis-Diamminedichloroplatinum(II),cis-Dichlorodiammineplatinum(II),Biocisplatinum,Dichlorodiammineplatinum,NSC-119875,Platidiam,Platino,Platinol,cis-Diamminedichloroplatinum,cis-Platinum,Diamminodichloride, Platinum,cis Diamminedichloroplatinum,cis Platinum
D004093	Dihydropteridine Reductase	An enzyme that catalyzes the reduction of 6,7-dihydropteridine to 5,6,7,8-tetrahydropteridine in the presence of NADP+. Defects in the enzyme are a cause of PHENYLKETONURIA II. Formerly listed as EC 1.6.99.7.	6,7-Dihydropteridine Reductase,6,7 Dihydropteridine Reductase,Reductase, 6,7-Dihydropteridine,Reductase, Dihydropteridine
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man