transaminázy

Transaminases, also known as aminotransferases, are a group of enzymes that play a crucial role in amino acid metabolism. Their primary function is to catalyze the transfer of an amino group (–NH2) from one molecule to another, typically from an amino acid to a keto acid. This reaction is essential for the synthesis and degradation of amino acids, which are the building blocks of proteins and are involved in numerous metabolic pathways.

The general reaction catalyzed by transaminases involves the transfer of an amino group from an amino acid to an alpha-keto acid. This results in the formation of a new amino acid and a new alpha-keto acid. The coenzyme pyridoxal phosphate (PLP), a derivative of vitamin B6, is required for the activity of most transaminases. PLP acts as a carrier of the amino group during the catalytic process.

Transaminases are found in various tissues and cellular compartments, with high concentrations often observed in the liver, heart, muscles, and kidneys. Certain transaminases are particularly significant as biomarkers in clinical diagnostics. For example, elevated levels of aspartate transaminase (AST) and alanine transaminase (ALT) in the blood serum can indicate damage to liver cells, heart muscle, or skeletal muscle. Measuring these enzyme levels is a common practice for assessing liver function and diagnosing conditions such as hepatitis, cirrhosis, and myocardial infarction. Other important transaminases include gamma-glutamyl transaminase (GGT) and alkaline phosphatase (ALP), which also provide insights into liver health and bile duct function.