Impact of Aging in Microglia-Mediated D-Serine Balance in the CNS

Figure 1

D-serine synthesis and degradation. D-serine is synthetized by isomerization of L-serine in a reaction catalyzed by the enzyme serine racemase which, in addition, also catalyzes the α,β-elimination of water from L-serine or D-serine to produce pyruvate and ammonia. Although serine racemase also has the potential to degrade D-serine through α,β-elimination of water, it is preferentially degraded through oxidation by the enzyme D-amino acid oxidase, generating hydroxypyruvate, peroxide, and ammonia.