MitoSciences: L-lactate dehydrogenase (pan) A and B chain (LDHA and LDHB)

UniProt Number:	P00338 , P07195
Alternate Names:	LDH heart subunit (LDH-H) Renal carcinoma antigen NY-REN-46 Cell proliferation-inducing gene 19 protein LDH muscle subunit Short name=LDH-M Renal carcinoma antigen NY-REN-59
Structure and Function:	Lactate dehydrogenase catalyzes the interconversion of pyruvate and lactate with concomitant interconversion of NADH and NAD⁺. It converts pyruvate to lactate when oxygen is absent or in short supply and it performs the reverse reaction during the Cori cycle in the liver. Functional lactate dehydrogenase are homo or hetero tetramers composed of M and H protein subunits encoded by the LDHA and LDHB genes respectively. The major isozymes of skeletal muscle and liver has four muscle (M) subunits; while the main isozymes for heart muscle contains four heart (H) subunits. The other variants contain both types of subunits.
Disease Associations:	Defects in LDHA are the cause of glycogen storage disease type 11 (GSD11). A metabolic disorder that results in exertional myoglobinuria, pain, cramps and easy fatigue. Elevated levels of LDHB indicates tissue breakdown in hemolytis or. Other disorders indicated by elevated LDH include cancer, meningitis, encephalitis, acute pancreatitis, and HIV. Defects in LDHB are a cause of hereditary LDHB deficiency. LDHB deficiency is usually asymptomatic.