transaminaatsioonides

Transaminatsioonides, also known as aminotransferaasides, are a class of enzymes that catalyze the transfer of an amino group from one molecule to another. This reaction is fundamental in amino acid metabolism, playing a crucial role in both the synthesis and degradation of amino acids. The general reaction involves an amino acid and an alpha-keto acid, resulting in the formation of a new amino acid and a new alpha-keto acid. Pyridoxal phosphate, a derivative of vitamin B6, acts as an essential coenzyme for most transaminating enzymes.

The process typically occurs in two steps. First, the amino group from the donor amino acid is transferred to pyridoxal phosphate, forming a pyridoxamine phosphate intermediate. In the second step, this intermediate then transfers the amino group to an acceptor alpha-keto acid, regenerating the pyridoxal phosphate and forming the new amino acid. Transaminases are widely distributed in nature, found in bacteria, plants, and animals. In humans, they are particularly abundant in the liver, heart, and muscles.

Several specific transaminases are important clinically. For instance, alanine transaminase (ALT) and aspartate transaminase (AST) are commonly measured in blood tests to assess liver function. Elevated levels of these enzymes can indicate liver damage due to various causes, including hepatitis, cirrhosis, or exposure to toxins. Other transaminases are involved in the synthesis of neurotransmitters and other vital molecules. The study of transaminations is essential for understanding metabolic pathways and diagnosing certain diseases.