Food Chemistry and Fish in Nutrition ( 2+1)

8.2.2.1. Transamination by transaminases

Transamination interconverts a pair of amino acids and a pair of keto acids, generally and α amino acid and a β -keto acid. Most amino acids undergo transamination. Exceptions are lysine, threonine, proline and hydroxy proline.

Since transaminations are freely reversible, transaminases or aminotransferases can function both in amino acid catabolism and biosynthesis. Pyridoxal phosphate resides at the catalytic site of all transaminases. Two transaminases viz Alanine-pyruvate transaminase and glutamate a -ketoglutarate transaminase present in mammalian tissues catalyse the transfer of amino group from most amino acids.