GOT/AST

GOT/AST (aspartate aminotransferase) is a pyridoxal phosphate-dependent aminotransferase that catalyzes the reversible transfer of amino groups between aspartate and α-ketoglutarate, thereby linking amino acid metabolism with the tricarboxylic acid cycle and cellular nitrogen flux^[1][2]. Mechanistically, GOT/AST supports the malate-aspartate shuttle, maintains intracellular NAD⁺/NADH balance, and contributes to biosynthetic pathways required for nucleotide and protein synthesis^[3]. In mammalian cells, AST exists as two closely related isoforms, the cytosolic enzyme GOT1 and the mitochondrial enzyme GOT2, which differ in subcellular localization and metabolic function despite substantial structural homology^[3][4]. Compared with GOT1, GOT2 is a central component of mitochondrial redox transfer and malate-aspartate shuttle activity, linking glycolytic metabolism with mitochondrial energy production^[3][4]. In disease settings, altered AST activity is widely associated with liver injury, cardiovascular disorders, metabolic dysfunction, and cancer-related metabolic reprogramming^[1][3][5]. Experimental studies further indicate that GOT1 and GOT2 support proliferative metabolism in tumor cells through regulation of glycolytic and glutamine-dependent pathways, making these enzymes useful metabolic targets in cancer research models^[4]. Therefore, characterization of GOT/AST isoform-specific functions provides a practical framework for investigating cellular bioenergetics, metabolic disease mechanisms, and metabolism-directed therapeutic strategies^[3][4].