Role of glutamate-52 in the mechanism of L-lactate dehydrogenase from Bacillus stearothermophilus

Abstract

A single residue of the NAD(H)-dependent lactate dehydrogenase (LDH) from Bacillus stearothermophilus has been changed in order to decrease substrate inhibition. The conserved aspartic acid residue at position 52 was replaced by glutamate using site-directed mutagenesis. The effect on substrate inhibition was measured. In the glutamate-52 mutant substrate inhibition is decreased twofold.