Transamination

α-ketoglutarate acts as the predominant amino-group acceptor and produces glutamate as the new amino acid.

Glutamate's amino group, in turn, is transferred to oxaloacetate in a second transamination reaction yielding aspartate.

For the reaction to complete, aminotransferases require participation of aldehyde containing coenzyme, pyridoxal-5'-phosphate (PLP), a derivative of Pyridoxine (Vitamin B6).

The Schiff base, which is conjugated to the enzyme's pyridinium ring, is the focus of the coenzyme activity.

ISBN 0-471-58589-0 • Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim.

Aminotransfer reaction between an amino acid and an alpha-keto acid
Ping Pong Bi Bi mechanism of PLP dependent enzyme catalyzed transamination. Aminotransferase reaction occurs in two stages consisting of three steps: Transimination, Tautomerisation and Hydolysis. In the first stage, alpha amino group of the aminoacid is transferred to PLP yielding an alpha ketoacid and PMP. In the second stage of the reaction, in which the amino group of PMP is transferred to a different alpha Ketoacid to yield a new alpha amino acid and PLP.