Aminotransferaasien

Aminotransferaasien, also known as transaminaases, are a group of enzymes that catalyze the transfer of an amino group from an amino acid to a keto acid. This reaction, called transamination, is a crucial step in the metabolism of amino acids, playing a vital role in both their synthesis and degradation. Aminotransferases are found in all living organisms, from bacteria to humans, and are particularly abundant in the liver, muscles, and heart.

The general reaction catalyzed by aminotransferases involves an alpha-amino acid and an alpha-keto acid. The amino group from the amino acid is transferred to the carbonyl carbon of the keto acid, forming a new amino acid and a new keto acid. This process often involves pyridoxal phosphate (PLP) as a coenzyme, which binds to the enzyme and facilitates the transfer of the amino group.

Aminotransferases are essential for numerous biological processes. They are involved in the synthesis of non-essential amino acids, allowing cells to produce amino acids they cannot obtain from their diet. They also play a role in the catabolism of amino acids, providing intermediates for the citric acid cycle and gluconeogenesis, pathways that generate energy and glucose, respectively.

In clinical diagnostics, levels of certain aminotransferases in the blood are used as biomarkers for tissue damage. For instance, elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the blood can indicate liver damage, such as that caused by hepatitis or cirrhosis. Similarly, elevated creatine kinase (CK) levels, which also act as an aminotransferase, can suggest muscle injury.