Conversion of <i>Lactobacillus pentosus</i> <scp>d</scp> -Lactate Dehydrogenase to a <scp>d</scp> -Hydroxyisocaproate Dehydrogenase through a Single Amino Acid Replacement

Abstract

The single amino acid replacement of Tyr52 with Leu drastically increased the activity of Lactobacillus pentosus NAD-dependent D-lactate dehydrogenase toward larger aliphatic or aromatic 2-ketoacid substrates by 3 or 4 orders of magnitude and decreased the activity toward pyruvate by about 30-fold, converting the enzyme into a highly active D-2-hydroxyisocaproate dehydrogenase.