title: Kinetic behaviour of soluble and mitochondrial bound lactate dehydrogenase.
abstract: Rabbit liver mitochondrial fraction shows lactate dehydrogenase activity. The kinetic behaviour of mitochondrial bound enzyme fits a bibi sequential type mechanism as well as the cytosolic rabbit liver lactate dehydrogenase. The bound enzyme has greater values of Km(NADH) and Km(pyruvate) than the soluble one, suggesting that binding induces a decrease in the affinity of both substrates. The behaviour of the free and the mitochondrial-bound enzyme is of the Michaelis-Menten type, but the kinetics of a mixture of rabbit liver cytosolic and mitochondrial-bound lactate dehydrogenase is sigmoidal, suggesting that a cooperative phenomenon takes place.
authors.affiliation: Department of Biochemistry and Physiology, Faculty of Chemistry, University of Barcelona.
authors.forename: M C
authors.initials: MC
authors.lastname: Sanz
authors.forename: M L
authors.initials: ML
authors.lastname: Sagrista
authors.forename: C
authors.initials: C
authors.lastname: Lluis
mesh_terms: D000818:Animals; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D046911:Macromolecular Substances; D008930:Mitochondria, Liver / Q000378:metabolism*; D011817:Rabbits; D012995:Solubility
chemical_list: D046911:Macromolecular Substances; D007770:L-Lactate Dehydrogenase