aminotransference

Aminotransference refers to a biochemical process involving the transfer of an amino group (-NH2) from one molecule to another. This reaction is catalyzed by a class of enzymes called aminotransferases, also known as transaminases. Aminotransferases are crucial in the metabolism of amino acids, playing a key role in both their synthesis and degradation.

The general mechanism of aminotransference involves the transfer of the amino group from an alpha-amino acid to an alpha-keto acid. In this reaction, the alpha-amino acid becomes an alpha-keto acid, and the alpha-keto acid becomes a new alpha-amino acid. Pyridoxal phosphate (PLP), a derivative of vitamin B6, is an essential cofactor for most aminotransferase enzymes. PLP participates in the reaction by forming a Schiff base intermediate with the amino group of the amino acid substrate.

Aminotransference reactions are vital for various physiological processes. They are central to the urea cycle, where excess amino groups are converted to urea for excretion. Furthermore, aminotransferases are involved in the synthesis of non-essential amino acids, allowing the body to produce amino acids it cannot obtain from the diet. The measurement of specific aminotransferase enzymes in the blood, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), is a common diagnostic tool in clinical medicine for assessing liver function and detecting tissue damage.