The essential amino acid lysine acts as precursor of glutamate in the mammalian central nervous system

Lysine has long been recognized as an essential amino acid for humans and t he lack or low supply of this compound in the diet may lead to mental and p hysical handicaps. Since lysine is severely restricted in cereals, the most important staple food in the world, the understanding of ifs biological ro les must be a major concern. Here we show that lysine is an important precu rsor for de novo synthesis of glutamate, the most significant excitatory ne urotransmitter in the mammalian central nervous system. We also show that t he synthesis of glutamate from lysine, which is carried out by the saccharo pine pathway, is likely to take place in neurons. (C) 2001 Federation of Eu ropean Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.