Serine racemase (SRR) (SRR)

Serine racemase (SRR) is a pyridoxal-5'-phosphate (PLP)-dependent enzyme primarily responsible for the synthesis of D-serine from L-serine in the mammalian brain [1, 4]. D-serine serves as a critical co-agonist at the glycine-binding site of the N-methyl-D-aspartate (NMDA) receptor, making SRR a key regulator of glutamatergic neurotransmission, synaptic plasticity, and memory formation [3, 5]. Beyond its racemase activity, the enzyme also catalyzes the beta-elimination of serine to produce pyruvate and ammonia, acting as a metabolic "bleed valve" for serine levels [4, 10]. Dysregulation of SRR and subsequent D-serine imbalance are implicated in various neurological disorders: low levels are associated with NMDA hypofunction in schizophrenia, while elevated levels contribute to excitotoxicity in stroke, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS) [1, 7, 8]. Consequently, SRR is a target for therapeutic intervention, with inhibitors being explored for neuroprotection and activators or D-serine supplementation for psychiatric conditions [2, 6, 12].

Other names

SRSRRILV1ISO1L-serine ammonia-lyaseD-serine ammonia-lyase

Inhibition of serine racemase to reduce D-serine levels and prevent NMDA receptor-mediated excitotoxicity in neurodegenerative diseases and stroke; or activation of the enzyme/supplementation of its product to enhance NMDA receptor function in psychiatric disorders like schizophrenia [1, 2, 6].