Oxidation of lactate by human serum.

The oxidation of lactate by lactate dehydrogenase of human serum is described, and the kinetics of the reaction are examined. It seems that at higher pH values which are optimal for the faster moving isoenzymes of lactate dehydrogenase, slower moving entities show only a part of their activity. In contrast, M type isoenzymes are active at lower pH values, where H type entities are partly inactivated.