Tat-NR2B9c

Tat-NR2B9c (Tat-NR2Bct; NA-1) is a postsynaptic density-95 (PSD-95) inhibitor, with EC₅₀ values of 6.7 nM and 670 nM for PSD-95d2 (PSD-95 PDZ domain 2) and PSD-95d1, respectively. Tat-NR2B9c disrupts the PSD-95/NMDAR interaction, inhibiting NR2A and NR2B binding to PSD-95 with IC₅₀ values of 0.5 μM and 8 μM, respectively. Tat-NR2B9c also inhibits neuronal nitric oxide synthase (nNOS)/PSD-95 interaction, and possesses neuroprotective efficacy^[1][2][5]. IC50 & Target:EC50: 6.7 nM (PSD-95d2), 670 nM (PSD-95d1)^[1]
NO synthase^[1] In Vitro: Tat-NR2B9c is a PSD-95 inhibitor, with an EC₅₀ of 6.7 nM for PSD-95d2, representing a >100-fold higher affinity for this domain than for PSD-95d1 (EC₅₀, 0.67 μM). Tat-NR2B9c inhibits NMDAR2A, NMDAR2B, and NMDAR2C binding to PSD-95, with IC₅₀s of 0.5 μM, ∼8 μM, and 0.75 μM, respectively.
Tat-NR2B9c also blocks the interaction between PSD-95 and nNOS with an IC₅₀ of ∼0.2 μM^[1].
Tat-NR2B9c reduces association of PSD-95 with GluN2B by ∼50% in the YAC128 striatum, decreases NMDA-induced p38 activation in YAC128 striatal tissue, but shows no effect on the NMDA-induced JNK activation^[2]. In Vivo: Tat-NR2B9c (10 nmol/g, i.v.) reduces infarction volume of male C57BL/6 mice, but has no effect at 3 nM/g^[3].