Cytoplasmic malate dehydrogenase from Phycomyces blakesleeanus: kinetics and mechanism.
The kinetics and reaction mechanism of cytoplasmic malate dehydrogenase (L-malate:NAD+ oxidoreductase, EC 1.1.1.37) from mycelium of Phycomyces blakesleeanus NRRL 1555 (-) in 0.1 M potassium phosphate buffer (pH 7.5) at 30 degrees C have been investigated. The initial rate and product inhibition studies were consistent with an ordered bi-bi mechanism that involved more than one kinetically significant ternary complex and also with the coenzyme binding first. The dissociation of the coenzyme from the enzyme-coenzyme complex appeared to be the slowest step in either direction of the reaction. The kinetic and rate constants for the individual steps of the reaction were determined.
D003593:Cytoplasm / Q000201:enzymology; D007700:Kinetics; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008433:Mathematics; D009090:Mucorales / Q000201:enzymology*; D009243:NAD; D010084:Oxidation-Reduction; D010800:Phycomyces / Q000201:enzymology*
D009243:NAD; D008291:Malate Dehydrogenase