[Inhibition of the malic enzyme from Acinetobacter calcoaceticus by NADPH and NADH].
The malic enzyme enriched from Acinetobacter calcoaceticus is inhibited by NADPH and NADH. The inhibition afforded by the reduced coenzymes is not affected by NAD+, AMP and 3'.5'-AMP. Against L-malate, NADPH inhibits the enzyme in a noncompetitive linear fashion (Ki = 1.5 x 10(-4) M), against NADP+, competitively linearly (Ki = 5.0 x 10(-5) M). While NADPH acted as a product inhibitor, NADH seems to be an allosteric effector of the malic enzyme, because with L-malate as the variable substrate in the double reciprocal plot, a nonlinear curve is obtained.
D000150:Acinetobacter / Q000201:enzymology*; D000494:Allosteric Regulation; D008291:Malate Dehydrogenase / Q000037:antagonists & inhibitors*; D009243:NAD / Q000494:pharmacology*; D009249:NADP / Q000494:pharmacology*
D009243:NAD; D009249:NADP; D008291:Malate Dehydrogenase
Hemmung des Malatenzyms aus Acinetobacter calcoaceticus durch NADPH and NADH