Glutamate receptor ionotropic NMDA type subunit 2B (GluN2B) amino-terminal domain zinc binding site (GluN2B ATD zinc site)

The Glutamate receptor ionotropic NMDA type subunit 2B (GluN2B) amino-terminal domain (ATD) zinc binding site is a specific allosteric regulatory region located on the GluN2B subunit of the N-methyl-D-aspartate (NMDA) receptor. The NMDA receptor is a heterotetrameric ion channel that plays a fundamental role in excitatory neurotransmission, synaptic plasticity, and memory formation in the brain (Karakas et al., 2011; Nature). While the GluN2A subunit possesses a high-affinity (nanomolar) zinc binding site, the GluN2B subunit contains a lower-affinity (micromolar) site within its clamshell-like ATD structure that mediates voltage-independent inhibition (Rachline et al., 2005; J Neurosci). This site is of significant therapeutic interest because the ATD of GluN2B also serves as the binding pocket for various selective negative allosteric modulators (NAMs), such as ifenprodil and traxoprodil, which are being investigated for treating conditions like treatment-resistant depression and chronic pain (Mony et al., 2009; Br J Pharmacol). Dysregulation of GluN2B-containing receptors is linked to several neurological disorders, including Alzheimer's and Parkinson's diseases, where excessive NMDA activity contributes to excitotoxicity (Hansen et al., 2021; Pharmacol Rev). Targeting the ATD zinc site or its adjacent pockets allows for the development of subtype-selective drugs that can modulate glutamatergic signaling with greater precision and fewer side effects than non-selective pore-blocking antagonists.

Other names

NR2B amino-terminal domain zinc siteGRIN2B N-terminal domain zinc siteGluN2B-Zn2+ binding siteNMDA receptor subunit 2B ATD zinc site

Negative allosteric modulation of the NMDA receptor channel opening probability through conformational changes in the amino-terminal domain (ATD) upon ligand binding.