Transamination (Importance Of Transaminases)
The first step in the catabolism of most L-amino acids, once they have reached the liver, is removal of the a-amino groups, promoted by enzymes called aminotransferases or transaminases. The effect of transamination reactions is to collect the amino groups from many different amino acids in the form of Lglutamate. The glutamate then functions as an amino group donor for biosynthetic pathways or for excretion pathways that lead to the elimination of nitrogenous waste products. Cells contain different types of aminotransferases. 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 the metabolism of molecules with amino groups. Pyridoxal phosphate functions as an intermediate carrier of amino groups at the active site of aminotransferases.
