Cytoplasmic Aspartate Aminotransferase (cAST) is an enzyme that plays a crucial role in amino acid metabolism within the cell. It is classified as an aminotransferase, also known as transaminase, which catalyzes the transfer of an amino group from an amino acid to a keto acid, resulting in the formation of a new amino acid and a different keto acid.
cAST specifically acts on the amino acid aspartate, transferring its amino group to a keto acid, usually α-ketoglutarate. This reaction generates glutamate and oxaloacetate, both of which are important metabolites involved in various metabolic pathways. Glutamate, for instance, serves as a precursor for the synthesis of other amino acids, neurotransmitters, and nucleotides, while oxaloacetate can be further utilized in the citric acid cycle as an intermediate for energy production.
This particular form of aspartate aminotransferase is localized within the cytoplasm of the cell, accounting for its name. The cytoplasmic compartment contains a broad range of metabolic activities, making cAST crucial for maintaining amino acid homeostasis and overall cellular metabolism.
cAST activity is found in various tissues and organs, including the liver, heart, and skeletal muscles, reflecting its role in fundamental cellular processes. Abnormal levels or mutations of cAST can lead to metabolic disorders and diseases, such as liver dysfunction, which can result in elevated levels of the enzyme in the blood. Thus, measuring cAST levels is often used as a diagnostic marker for evaluating liver function.
