|Detection of Human, Mouse, and Rat Lactate Dehydrogenase A/LDHA by Western Blot. Western blot shows lysates of Daudi human Burkitt's lymphoma cell line, MOLT‑4 human acute lymphoblastic leukemia cell line, mouse skeletal muscle tissue, and rat skeletal muscle tissue. PVDF membrane was probed with 0.5 µg/mL of Sheep Anti-Human/Mouse/Rat Lactate Dehydrogenase A/LDHA Antigen Affinity-purified Polyclonal Antibody (Catalog # AF7304) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for Lactate Dehydrogenase A/LDHA at approximately 36 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.|
LDHA (lactate dehydrogenase A chain; also LDH-M and PIG-19) is a 34-36 kDa member of the LDH family of enzymes. It is a part of a cytoplasmic complex that is found principally in hepatocytes and skeletal muscle. The LDHA complex catalyzes the conversion of pyruvate to lactate, thereby generating NAD, the final step in anerobic glycolysis. This NAD is essential for the subsequent generation of ATP. Human LDHA is 332 amino acids (aa) in length. It contains an N-terminal coenzyme binding region, a central catalytic site, and at least nine utilized Lys acetylation and two Tyr phosphorylation sites. It also undergoes ISGylation where a 17 kDa product of the ISG15 gene is covalently attached to LDHA in a ubiquitin-like manner. LDHA forms tetramers composed of two dimers of varying composition. The tetramer may be homotetrameric (four monomers), or contain from one to three substitute LDHB monomers typically found in heart muscle. There are multiple splice variants. One possesses a five aa substitution for aa 237-332, a second contains a 45 aa substitution for aa 230-332, a third shows a deletion of aa 82-139, while a fourth utilizes an alternative start site 29 aa upstream of the standard site. Over aa 2-92, human LDHA shares 93% aa sequence identity with mouse LDHA.