Behind substrate specificity switch in lactate dehydrogenase: Active-site loop dynamics and epistatic enhancement.
Substrate specificity in lactate dehydrogenases (LDHs) controls metabolic flux and remains a central challenge in enzyme engineering, particularly when closely related substrates differ by only a single carboxylate group. Although Q102 (equivalent to Gln86 in Geobacillus stearothermophilus L-LDH) is recognized as a can...