Tat-NR2B9c (NA-1) is a 20-mer peptide composed of a membrane-permeant HIV-1 T at protein transduction domain sequence (a.a. 47-57) N-terminal to the NMDA receptor (NMDAR) GluN2B carboxyl tail sequence KLSSIESDV th at blocks intracellular NMDAR-PSD-95 interaction-induced neurotoxic signaling without affecting NMDAR-mediated synaptic activity or calcium influx. NA-1 protects cultured cortical neurons from NMDA excitotoxicity (50 nM; 20/40/100 μM NMDA) and reduces focal ischemic brain damage in rats in vivo (3 μmol/kg iv. bolus 1 hr post MCAO onset).
