To design a peptide disrupting the interaction between N-methyl-D-aspartate receptors-2B (NR2B) and postsynaptic density protein-95 (PSD-95), a gene fragment encoding a chimeric peptide was constructed using polymerase chain reaction and ligated into a novel expression vector for recombinant expression in a 17 RNA polymerase-based expression system. The chimeric peptide contained a fragment of the cell membrane transduction domain of the human immunodeficiency virus type1 (HIV-1) Tat, a influenza virus hemagglutinin (HA) epitope-tag, and the C-terminal 9 amino acids of NR2B (NR2B9c). We named the chimeric peptide Tat-HA-NR2B9c. The expression plasmid contained a gene fragment encoding the Tat-HA-NR2B9c was ligated to the C-terminal fragment of L-asparaginase (AnsB-C) via a unique acid labile Asp-Pro linker. The recombinant fusion protein was expressed in inclusion body in Escherichia coli under isopropyl beta-D-1-thiogalactopyranoside (IPTG) and purified by washing with 2 M urea, solubilizing in 4 M urea, and then ethanol precipitation. The target chimeric peptide Tat-HA-NR2B9c was released from the fusion partner following acid hydrolysis and purified by isoelectric point precipitation and ultrafiltration. SDS-PAGE analysis and MALDI-TOF-MS analysis showed that the purified Tat-HA-NR2B9c was highly homogeneous. Furthermore, we investigated the effects of Tat-HA-NR2B9c on ischemia-induced cerebral injury in the rats subjected to middle cerebral artery occlusion (MCAO) and reperfusion. and found that the peptide reduced infarct size and improved neurological functions. (C) 2012 Elsevier Inc. All rights reserved.