LDHB Human

Lactate Dehydrogenase B (LDH-B), also known as L-lactate dehydrogenase B chain, is an enzyme that plays a crucial role in the metabolic pathway of glycolysis. It catalyzes the interconversion of pyruvate and lactate with the concomitant interconversion of NADH and NAD+. This enzyme is particularly important in tissues that rely heavily on anaerobic glycolysis, such as muscle tissue and certain types of cancer cells.

LDH-B is a member of the lactate dehydrogenase family, which consists of several isoenzymes. These isoenzymes are tetrameric proteins composed of different combinations of two subunits: LDH-A (muscle type) and LDH-B (heart type). The LDH-B subunit is predominantly found in the heart, kidneys, and red blood cells. The enzyme’s active site binds to pyruvate and NADH, facilitating the reduction of pyruvate to lactate while oxidizing NADH to NAD+.

Recombinant human LDH-B is produced using Escherichia coli (E. coli) expression systems. The gene encoding LDH-B is cloned into a suitable vector and introduced into E. coli cells. These cells are then cultured under conditions that promote the expression of the LDH-B protein. The recombinant protein is subsequently purified using conventional chromatography techniques to achieve high purity levels, typically greater than 90% .

Recombinant LDH-B is widely used in biochemical research and clinical diagnostics. It serves as a valuable tool for studying metabolic pathways, enzyme kinetics, and the effects of various inhibitors on LDH activity. In clinical settings, LDH levels are often measured as a marker for tissue damage, hemolysis, and certain types of cancer. Elevated LDH levels can indicate conditions such as myocardial infarction, liver disease, and hemolytic anemia.

The specific activity of recombinant LDH-B is typically greater than 300 units per milligram. One unit of LDH-B activity is defined as the amount of enzyme that catalyzes the conversion of 1.0 micromole of pyruvate to lactate per minute at pH 7.5 and 37°C. The enzyme’s activity can be measured using spectrophotometric assays that monitor the change in absorbance at 340 nm due to the oxidation of NADH .

Recombinant LDH-B is an active protein and may elicit a biological response in vivo. Therefore, it should be handled with caution. It is typically supplied in a buffer containing glycerol, Tris HCl, and other stabilizing agents to maintain its stability and activity during storage and use .