Tomizawa M, Casida J E
Department of Environmental Science, Policy and Management, University of California, Berkeley 94720-3112, USA.
Neurosci Lett. 1997 Nov 21;237(2-3):61-4. doi: 10.1016/s0304-3940(97)00811-2.
The novel synthetic nicotinoid insecticide imidacloprid is a high affinity ligand for the insect nicotinic acetylcholine receptor (nAChR). The goal of this study is to identify the ligand- and insecticide-binding subunit of Drosophila nAChR with a novel [125I]azidonicotinoid ([125I]AN) photoaffinity probe modeled on imidacloprid. [125I]AN photoaffinity labels a single polypeptide in Drosophila head membranes corresponding in molecular mass to 66 kDa at a specific site inhibited by various cholinergic ligands including (-)-nicotine, cytisine, carbachol, alpha-bungarotoxin and d-tubocurarine as well as the insecticides imidacloprid and acetamiprid, pharmacologically consistent with the ligand- and insecticide-binding subunit. The Drosophila nAChR, isolated with three putative subunits (69, 66 and 61 kDa) using a nicotinoid-agarose affinity column, is labeled by [125I]AN primarily at the 66 kDa subunit and secondarily at the 61 kDa subunit. Clearly, the novel synthetic nicotinoid insecticides are valuable contributors in exploring the structure and function of the Drosophila nAChR.
新型合成烟碱类杀虫剂吡虫啉是昆虫烟碱型乙酰胆碱受体（nAChR）的高亲和力配体。本研究的目的是利用一种以吡虫啉为模型的新型[125I]叠氮烟碱类（[125I]AN）光亲和探针，鉴定果蝇nAChR的配体和杀虫剂结合亚基。[125I]AN光亲和标记果蝇头部膜中的一条单一多肽，其分子量在66 kDa，该位点受到多种胆碱能配体的抑制，包括（-）-尼古丁、金雀花碱、卡巴胆碱、α-银环蛇毒素和d-筒箭毒碱，以及杀虫剂吡虫啉和啶虫脒，在药理学上与配体和杀虫剂结合亚基一致。使用烟碱类琼脂糖亲和柱分离出具有三个假定亚基（69、66和61 kDa）的果蝇nAChR，[125I]AN主要标记66 kDa亚基，其次标记61 kDa亚基。显然，新型合成烟碱类杀虫剂在探索果蝇nAChR的结构和功能方面具有重要作用。
