Pyridoxal 5′-phosphate (PLP)

Pyridoxal 5′-phosphate (PLP) is the active form of vitamin B6 and serves as an essential chemical cofactor for over 140 distinct enzymatic activities in humans, mainly those catalyzing reactions involving amino acid transformations such as transamination, decarboxylation, deamination, and racemization[1][5][6]. PLP forms a covalent Schiff base with the active-site lysine of PLP-dependent enzymes, acting as an electron sink to stabilize reaction intermediates[1][2][6]. PLP-dependent enzymes are found across all domains of life and participate in diverse metabolic pathways, including neurotransmitter production, amino acid biosynthesis and degradation, and glycogen metabolism[1][5][6]. Deficiencies or dysfunction of PLP or its dependent enzymes are implicated in neurological, hematological, and metabolic diseases[5].

Other names

Pyridoxal phosphateP5PVitamin B6 phosphate

Cofactor for transamination, decarboxylation, deamination, racemization, and other amino acid-related enzymatic reactions Functions by forming Schiff base (aldimine) linkages with enzyme lysine residues, enabling stabilization of reaction intermediates