Pyridoxal-5 -phosphate biochemical function

The fundamental biochemical function of pyridoxal-5 -phosphate is the formation of aldimines with a-amino acids that stabilize the development of carbanionic character at the a and /3 carbons of a-amino acids in intermediates, such as those in figures 10.4b and c. Enzymes acting alone cannot stabilize these carbanions and so cannot, by themselves, catalyze reactions requiring their formation as intermediates. 

Biochemical functions pyridoxal phosphate is essential for aminotransferase (transamination) reactions in amino aoid metabolism and so is needed both for biosynthesis of the non-essential amino acids and also for amino acid oxidation for energy metabolism. Also an Important component of glycogen phosphorylase... 

Many of the biochemical reactions of amino acids require pyridoxal 5 -phosphate (PLP), the active form of vitamin 65, as a coenzyme. Before acting on an amino acid, PLP uses its aldehyde function to form an imine with file amino group of a lysine side chain of a protein. 

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