Biomaterial Database

Fluorescence stopped-flow studies on the binding of 1,N6-etheno-NAD to bovine liver glutamate dehydrogenase. 1988

R Favilla, and S R Martin, and P M Bayley

Department of Physics, University of Parma, Italy.

Fluorescence stopped-flow techniques have been used to investigate the binding of the oxidised coenzyme eNAD to bovine liver glutamate dehydrogenase (L-glutamate:NAD(P)+ oxidoreductase (deaminating), EC 1.4.1.3) saturated with glutarate, a substrate analogue, by following the transient kinetics of fluorescence intensity changes associated with changes in the binding of 1,N6-etheno-NAD (eNAD) to the enzyme, using displacement by NAD, NADP, ADP or GTP. Computer simulations of the various kinetic models provide a detailed picture of the molecular interactions between the active site (site I) and regulatory sites (sites II and III), specific for adenine and guanine nucleotides, respectively. The observed enhancement of the eNAD dissociation rate constant from site I can satisfactorily be accounted for as being due to the effect of ADP or NAD (and to a lesser extent NADP) binding to site II. This provides a mechanism for the allosteric activation of this enzyme via a predominantly intrasubunit interaction. By contrast the isomerisation of the enzyme induced by ADP alone is markedly slowed down by the occupancy of site I by eNAD in the presence of glutarate. The inhibitory effect of the allosteric effector GTP correlates with a tightening of eNAD binding, causing a decrease of the coenzyme dissociation rate constant followed by a slow isomerisation of the enzyme complexed with eNAD and glutarate.

UI	MeSH Term	Description	Entries
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
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D002417	Cattle	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.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D005453	Fluorescence	The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
D005969	Glutamate Dehydrogenase	An enzyme that catalyzes the conversion of L-glutamate and water to 2-oxoglutarate and NH3 in the presence of NAD+. (From Enzyme Nomenclature, 1992) EC 1.4.1.2.	Dehydrogenase, Glutamate
D005977	Glutarates	Derivatives of glutaric acid (the structural formula (COO-)2C3H6), including its salts and esters.	Glutarate
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine
D000465	Algorithms	A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.	Algorithm
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia