Transaminaatioreitteihin

Transaminaatioreitteihin refers to the metabolic pathways involving transamination reactions. Transamination is a crucial biochemical process where an amino group is transferred from an amino acid to a keto acid. This reaction is catalyzed by enzymes called transaminases, also known as aminotransferases. These enzymes typically require pyridoxal phosphate (PLP), a derivative of vitamin B6, as a coenzyme.

The general reaction involves the transfer of the alpha-amino group from an amino acid to the alpha-keto group of a keto acid. This results in the formation of a new amino acid and a new keto acid. This process is fundamental for both the synthesis and degradation of amino acids. For example, transamination is key in the synthesis of non-essential amino acids, where a precursor keto acid is converted into an amino acid by accepting an amino group from an existing amino acid. Conversely, in amino acid catabolism, transamination initiates the breakdown of excess amino acids, preparing them for further metabolic processing, often leading to their eventual conversion into intermediates of the citric acid cycle or for gluconeogenesis.

Several important transamination reactions occur in living organisms. For instance, the alanine transaminase (ALT) and aspartate transaminase (AST) enzymes are particularly well-known and are often measured in blood tests as indicators of liver health. AST, for example, plays a role in the metabolism of both amino acids and the citric acid cycle. Transamination is thus a central hub in amino acid metabolism, linking amino acid pools to energy production and the synthesis of other biomolecules.