Biomaterial Database

Overall kinetic mechanism of 6-phosphogluconate dehydrogenase from Candida utilis. 1993

A J Berdis, and P F Cook

Department of Biochemistry, Texas College of Osteopathic Medicine, Fort Worth 76107.

A complete initial velocity study of the 6-phosphogluconate dehydrogenase from Candida utilis at pH 7 and 25 degrees C in both reaction directions suggests a rapid equilibrium random kinetic mechanism with dead-end E:NADP:(ribulose 5-phosphate) and E:NADPH:(6-phosphogluconate) complexes. Like substrate-product (NADP/NADPH and 6-phosphogluconate/ribulose 5-phosphate) pairs are competitive whatever the concentration of the other substrates but noncompetitive versus the other substrates, e.g., NADPH exhibits noncompetitive inhibition versus 6-phosphogluconate. This trend also holds true for all dead-end analogs, e.g., ATP-ribose is competitive versus NADP and noncompetitive versus 6-phosphogluconate. A quantitative analysis of the kinetic inhibition constants supports the assignment of kinetic mechanism. The ratio of the maximum velocities in the oxidative decarboxylation and reductive carboxylation directions is 75.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008962	Models, Theoretical	Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Experimental Model,Experimental Models,Mathematical Model,Model, Experimental,Models (Theoretical),Models, Experimental,Models, Theoretic,Theoretical Study,Mathematical Models,Model (Theoretical),Model, Mathematical,Model, Theoretical,Models, Mathematical,Studies, Theoretical,Study, Theoretical,Theoretical Model,Theoretical Models,Theoretical Studies
D009249	NADP	Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)	Coenzyme II,Nicotinamide-Adenine Dinucleotide Phosphate,Triphosphopyridine Nucleotide,NADPH,Dinucleotide Phosphate, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide Phosphate,Nucleotide, Triphosphopyridine,Phosphate, Nicotinamide-Adenine Dinucleotide
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010734	Phosphogluconate Dehydrogenase	An enzyme of the oxidoreductase class that catalyzes the reaction 6-phospho-D-gluconate and NADP+ to yield D-ribulose 5-phosphate, carbon dioxide, and NADPH. The reaction is a step in the pentose phosphate pathway of glucose metabolism. (From Dorland, 27th ed) EC 1.1.1.43.	6-Phosphogluconate Dehydrogenase,6 Phosphogluconate Dehydrogenase,Dehydrogenase, 6-Phosphogluconate,Dehydrogenase, Phosphogluconate
D002175	Candida	A genus of yeast-like mitosporic Saccharomycetales fungi characterized by producing yeast cells, mycelia, pseudomycelia, and blastophores. It is commonly part of the normal flora of the skin, mouth, intestinal tract, and vagina, but can cause a variety of infections, including CANDIDIASIS; ONYCHOMYCOSIS; VULVOVAGINAL CANDIDIASIS; and CANDIDIASIS, ORAL (THRUSH).	Candida guilliermondii var. nitratophila,Candida utilis,Cyberlindnera jadinii,Hansenula jadinii,Lindnera jadinii,Monilia,Pichia jadinii,Saccharomyces jadinii,Torula utilis,Torulopsis utilis,Monilias