Pyridoxal phosphate (PLP, Pyridoxal
5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme
in a variety of enzymatic reactions. The Enzyme Commission has
catalogued more than **0 PLP-dependent activities, which is
equivalent to about 4% of all classified activities. The
versatility of PLP arises from its ability to covalently bind the
substrate, and then to act as an electrophilic catalyst, thereby
stabilizing different types of carbanionic reaction
intermediates.
