Drosophila nicotinic receptors: evidence for imidacloprid insecticide and alpha-bungarotoxin binding to distinct sites.
Drosophila nicotinic receptors: evidence for imidacloprid insecticide and alpha-bungarotoxin binding to distinct sites.
复制标题
果蝇烟碱受体：吡虫啉杀虫剂和α-银环蛇毒素结合到不同位点的证据。
DOI：
10.1016/j.neulet.2004.08.040
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发表时间：
2004
影响因子：
2.5
通讯作者：
Casida,JohnE
中科院分区：
文献类型：
--
作者：
Zhang,Nanjing;Tomizawa,Motohiro;Casida,JohnE
The principal mammalian brain nicotinic acetylcholine receptors (nAChRs) are the α-bungarotoxin (α-BGT)-insensitive α4β2 and the α-BGT-sensitive α7 subtypes assayed with radiolabeled nicotinoids and α-BGT, respectively. Drosophila head membranes bind the insecticide radioligand [3H]imidacloprid ([3H]IMI) and [3H]α-BGT with KD5.7 and 2.7nM and Bmax980 and 1400fmol/mg protein, respectively. The hypothesis that [3H]IMI at 2.5 or 20nM and [3H]α-BGT at 1 or 10nM bind to distinct sites or subtypes is tested by using these radioligands alone and together in simultaneous dual binding experiments. These studies show no interference by one radioligand in the binding of the other one, i.e., independent binding, and that both unlabeled IMI and α-BGT give biphasic displacement curves. The pharmacological profiles of [3H]IMI and [3H]α-BGT suggest distinct binding sites for the two radioligands. These findings are consistent with those obtained with hybrid receptors assembled from Drosophila α subunits and a vertebrate β subunit and with immunological and protein biochemical approaches. This study, therefore, provides direct evidence for distinct IMI- and α-BGT-sensitive sites or subtypes in Drosophila brain.
