Lactate dehydrogenase B chain (LDH-B)

Lactate dehydrogenase B chain (LDH-B) is a protein subunit encoded by the LDHB gene. It assembles into tetramers (homotetramers or heterotetramers with LDH-A subunits) to form lactate dehydrogenase isoenzymes. LDH-B is most highly expressed in the heart and other aerobic tissues. The enzyme catalyzes the interconversion between pyruvate and lactate, coupled with NAD^+^/NADH cycling, playing a critical role in energy metabolism, especially during anaerobic glycolysis. It participates in metabolic adaptation, particularly in tissues needing rapid shifts between aerobic and anaerobic metabolism. Total LDH as well as specific isoforms (including LDH-B-rich forms) are used clinically as non-specific biomarkers for tissue injury and pathological conditions, particularly in cardiac and oncology contexts. Mutations in LDHB can cause a rare biochemical deficiency but do not typically produce clinical symptoms

Other names

L-lactate dehydrogenase B chainlactate dehydrogenase H chainLDH heart subunitLDH-BLDH-HLDHB_HUMANLDHBD

Enzyme inhibition (for research; inhibitors block the pyruvate–lactate conversion and alter cellular metabolism); Diagnostic biomarker usage (monitoring of tissue injury or disease)