Used in Transamination:

Transamination (first step in the catabolism of amino acids) is catalysed by transaminases. These enzymes use pyridoxal phosphate which is active form of pyridoxine (vitamin B6) as coenzyme. Biochemical Roles of Pyridoxine Trans-sulfuration Simple decarboxylation (mainly histidine, gluatamate, tryptophan) ALA synthase (Haem synthesis) Cystathionine synthase (synthesis of Cysteine) Alkaline phosphatase Glycogen phosphorylase (RLE in glycogen breakdown) Tryptophan metabolism, synthesis of Niacin (vitamin B3)