Merck Millipore NK1 Tachykinin receptor Membrane Preparation

The tachykinin peptide family in mammals comprises three peptides, substance P, neurokinin A and neurokinin B, which bind to the tachykinin receptor family of GPCRs, NK1, NK2 and NK3 (Severini et al., 2002). Tachykinins have prominent activity in the GI system, in which they stimulate intestinal contraction and salivation. These effects are mediated by NK1 and NK2, and an antagonist of NK1, aprepitant, is used for treatment of chemotherapy-induced emesis (Rupniak and Kramer, 1999). The NK1 tachykinin receptor is expressed in brain, and is thought to be involved in depression and nociception (Saria, 1999). Although NK1 appears to promote nociception in animal models, the significance of this activity is controversial, as antagonists of NK1 have not proven efficacious in pain relief in humans (Hill, 2000). Chemicon's NK1 membrane preparations are crude membrane preparations made from our proprietary stable recombinant cell lines to ensure high-level of GPCR surface expression; thus, they are ideal HTS tools for screening of antagonists of NK1 interactions with Substance P. The membrane preparations exhibit a Kd of 0.28-0.4 nM for [125I]-Substance P. With 10 µg/well NK1 Membrane Prep and 0.25 nM [125I]-Substance P, a greater than 5-fold signal-to-background ratio was obtained.