D-Lactic Dehydrogenase from Lactobacillus leichmannii

Research area: Cell Signaling
Lactate Dehydrogenase (LDH) is classified as an oxidoreductase and is found in various organisms, including both plants and animals. LDH is widely distributed across all tissues, with high concentrations in muscle, kidney, and liver. The genes encoding LDH are LDHA, LDHB, LDHC, and LDHD. The D-isomer is produced by LDHD. There are two types of D-LDHs: NAD-dependent D-LDHs and FAD-dependent D-LDHs.

D-Lactic Dehydrogenase from Lactobacillus leichmannii has been used:

• in lactate dehydrogenase activity for testing the chaperone activity of proteins
• to test the kinase activities of purified thiamine monophosphate(ThiM)
• in NADH-coupled steady-state ATPase assay
• to determine cellular lactate

In the food industry, the primary catalysis is coupled to conversion of NADH and H⁺ to NAD⁺ with diaphorase coupled with converting the non-fluorescent resazurin to the highly fluorescent substance resorufin to measure the content of D-lactate in food products.

D-lactic dehydrogenase catalyzes the conversion of pyruvate into D-lactate, with oxidation of NADH to NAD⁺. D-lactic dehydrogenase can also catalyze the reverse reaction, conversion of D-lactate into pyruvate with reduction of NAD⁺ to NADH.

It acts as a crucial checkpoint in gluconeogenesis and DNA metabolism. Elevated levels of LDH in the blood have been observed in various conditions, including heart attacks, cancers, liver disease, muscle trauma, anemia, bone fractures, and infections such as encephalitis, human immunodeficiency virus(HIV), and meningitis. LDH also serves as a non-specific marker of tissue turnover, which is a normal metabolic process. Additionally, reduced D-LDH activity has been found in case of mutations in LDHD found in patients with D-lactic acidosis.

Lyophilized powder containing phosphate buffer salts

D-lactic dehydrogenase catalyzes the conversion of pyruvate into D-lactate, with oxidation of NADH to NAD⁺. D-lactic dehydrogenase can also catalyze the reverse reaction, conversion of D-lactate into pyruvate with reduction of NAD⁺ to NADH.

One unit will reduce 1.0 μmole of pyruvate to D-lactate per min at pH 7.0 at 25 °C.