What transformation does AST catalyze?

Aspartate aminotransferase (AST) is an enzyme that plays a crucial role in amino acid metabolism, specifically in the transamination process. Its primary function is to catalyze the conversion of aspartate to oxaloacetate. This reaction involves the transfer of an amino group from aspartate to α-ketoglutarate, resulting in the formation of oxaloacetate and glutamate.

This transformation is important because oxaloacetate is a key intermediate in the citric acid cycle (Krebs cycle), serving as an important entry point for carbohydrates, amino acids, and fatty acids into cellular energy production. Additionally, this reaction is vital in the urea cycle and helps maintain the nitrogen balance in the body.

Understanding this specific transformation highlights the critical role AST plays in metabolic pathways and its clinical significance, especially in conditions related to liver function where AST levels may become elevated.