Virginia Research Day 2022

Undergraduate Student Research Biomedical

04 Role of agonist binding domain inter-subunit interaction sites in CNS4 & CNS42 induced modulation of NMDA receptors

Seth Boehringer; Alyssa Ingram; Blaise Costa Corresponding author: sethcb@vt.edu

VCOM Virginia Virginia-Maryland College of Veterinary Medicine

indicate that CNS4 and CNS42 modulate NMDA receptors in a subunit-specific and agonist concentration-dependent manner. Further studies on the ABD would provide more insights into the role of intersubunit interaction sites and putative binding sites of these compounds. Identifying the binding sites would help develop higher affinity drug-like compounds that can be used for preclinical studies on animal models of depression and PTSD.

electrophysiology assay. Results reveal that all four alanine mutations reduced glutamate efficacy, an effect CNS4 produced in wild-type GluN1/2A receptors. However, in contrast to GluN1-N521A, the N521D mutant significantly increased the efficacy of glutamate. Further, in the presence and absence of GluN1 binding co-agonist glycine, CNS4 disproportionately affected glutamate efficacy on wild type GluN1/2A and GluN1-E781A/2A receptors. On the other hand, CNS42 potentiates GluN1/2A and minimally inhibits 1/2C and 1/2D receptors when activated by saturating concentration of (100µM) glutamate; this activity was reversed when activated with submaximal concentration (0.3µM) glutamate. Overall, the results

N-methyl-D-aspartate (NMDA) subtype of glutamate receptors is involved in human brain function and pathogenesis of neuropsychiatric disorders. Development of compounds to modulate the NMDA receptor function is of great pharmaceutical and clinical importance. CNS4 and its close congener CNS42 are identified to be modulating NMDA receptor subtypes based on agonist concentration. In the present study, we have made point mutations (N521A, N521D, K531A, Y535A & E781A) in the GluN1 subunit agonist binding domain (ABD) intersubunit interaction site-I, II, and III and co-expressed these mutants with wild type GluN2A subunits and studied changes in glutamate efficacy using

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