[Regulation of enzyme activity in adsorptive enzyme systems. III. Interaction of pig muscle lactate dehydrogenase with F-actin].
The binding of pig skeletal muscle lactate dehydrogenase by F-actin has been studied using the sedimentation method in 10 mM Tris-acetate buffer, pH 6.0 at 20 degrees C. Adsorption capacity of F-actin is equal to (1 +/- 0.1) . 10(-5) moles of lactate dehydrogenase per 1 g of actin. NADH decreases the affinity of F-actin with respect to lactate dehydrogenase. The binding of lactate dehydrogenase by F-actin in diminishing the rate of enzymatic reduction of alpha-ketoglutarate. The microscopic dissociation constant for the complex of the enzyme with F-actin which is estimated from the dependence of the enzymatic reaction rate of F-actin concentration at saturating NADH concentrations is equal (3.0 +2- 0.5) . 10(-7) M. It has been shown that the bound enzyme is characterized by the greater value of Km and the lower value of Vmax in comparison to the free enzyme.
D000199:Actins / Q000378:metabolism*; D000818:Animals; D004800:Enzymes, Immobilized / Q000378:metabolism*; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D009132:Muscles / Q000201:enzymology*; D013552:Swine
D000199:Actins; D004800:Enzymes, Immobilized; D007770:L-Lactate Dehydrogenase
Reguliatsiia aktivnosti fermentov v adsorbtsionnykh fermentnykh sistemakh. III. Vzaimodeĭstvie laktatdegidrogenazy iz myshts svin'i s F-aktinom.