Biosynthesis of Some Neurotransmitters from Amino Acids

(Nelson and Cox, Lehninger - Principles of Biochemistry, p.879)

Many important neurotransmitters are primary or secondary amines, derived from amino acids. A common denominator of many of these pathways is amino acid PLP dependent decarboxylation (shaded in pink).

All aminotransferases have the same prosthetic group and the same reaction mechanism. The prosthetic group is pyridoxal phosphate (PLP), the coenzyme form of pyridoxine, or vitamin B6. Its primary role in cells is in metabolism of molecules with amino groups. (ibid, p. 677).