| abstract |
There is a high level of D-serine in the mammalian brain, which, it seems, is an endogenous binding site of the "glycine region" of the NMDA receptors. We purified a soluble enzyme that catalyzes direct racemization of L-serine to D-serine from the mouse brain. The molecular weight of purified serine racemase is 37 kDA and requires pyroxidal 5'-phosphate for its activity. The enzyme is highly selective against L-serine, failing to racemate any other tested amino acid. We also detected the polynucleotide sequence encoding the serine racemase of mammals, including humans. Compounds that modulate the activity of mammalian serine serine racemase are useful for treating conditions and diseases caused by excessive stimulation of NMDA receptors, such as paralysis and various neurodegenerative diseases. |