Hamouda Ayman K, Jayakar Selwyn S, Chiara David C, Cohen Jonathan B
Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA,
J Mol Neurosci. 2014 Jul;53(3):480-6. doi: 10.1007/s12031-013-0150-1. Epub 2013 Oct 26.
For almost 30 years, photoaffinity labeling and protein microsequencing techniques have been providing novel insights about the structure of nicotinic acetylcholine receptors (nAChR) and the diversity of nAChR drug binding sites. Photoaffinity labeling allows direct identification of amino acid residues contributing to a drug binding site without prior knowledge of the location of the binding site within the nAChR or the orientation of the ligand within the binding site. It also distinguishes amino acids that contribute to allosteric binding sites from those involved in allosteric modulation of gating. While photoaffinity labeling was used initially to identify amino acids contributing to the agonist binding sites and the ion channel, it has been used recently to identify binding sites for allosteric modulators at subunit interfaces in the extracellular and the transmembrane domains, and within a subunit's transmembrane helix bundle. In this article, we review the different types of photoaffinity probes that have been used and the various binding sites that have been identified within the structure of nAChR, with emphasis on our recent studies of allosteric modulator binding sites.
近30年来，光亲和标记和蛋白质微测序技术为烟碱型乙酰胆碱受体（nAChR）的结构以及nAChR药物结合位点的多样性提供了新的见解。光亲和标记能够直接鉴定对药物结合位点有贡献的氨基酸残基，而无需事先了解结合位点在nAChR内的位置或配体在结合位点内的取向。它还能区分对变构结合位点有贡献的氨基酸与参与门控变构调节的氨基酸。虽然光亲和标记最初用于鉴定对激动剂结合位点和离子通道有贡献的氨基酸，但最近已被用于鉴定细胞外和跨膜结构域中以及亚基跨膜螺旋束内亚基界面处变构调节剂的结合位点。在本文中，我们综述了已使用的不同类型的光亲和探针以及在nAChR结构内已鉴定的各种结合位点，重点是我们最近对变构调节剂结合位点的研究。
