来自以色列金蝎的毒素III：昆虫钠通道上受体位点3的特异性探针。

Toxin III from Leiurus quinquestriatus quinquestriatus: a specific probe for receptor site 3 on insect sodium channels.

作者信息

Cestèle S, Gordon D, Kopeyan C, Rochat H

机构信息

Laboratoire de Biochimie, Impénierie des Protéines UNR6560, Université de la Méditeranneé CNRS IFR Jean Roche, Faculté de Médecine Nord Bd Pierre Dramard, Marseille, France.

出版信息

Insect Biochem Mol Biol. 1997 Jun;27(6):523-8. doi: 10.1016/s0965-1748(97)00027-1.

DOI:10.1016/s0965-1748(97)00027-1

PMID:9304794

Abstract

Scorpion toxin Lqq III binds to a single class of high affinity (Kd = 72 +/- 19 pM) and low capacity (Bmax = 2.5 +/- 0.2 pmol/mg) binding sites in cockroach neuronal membranes. Its binding was inhibited by Lqh alpha IT (IC50 = 80 +/- 30 pM) and sea-anemone toxin ATX II (IC50 = 2.5 +/- 0.3 nM), suggesting that Lqq III is a specific probe for receptor site 3 on cockroach sodium channels. This was confirmed by competitive binding experiments between 125I-Lqq III and scorpion alpha-toxins which have less toxicity in insects.

摘要

蝎毒素Lqq III与蟑螂神经元膜上一类高亲和力（解离常数Kd = 72 ± 19皮摩尔）和低容量（最大结合量Bmax = 2.5 ± 0.2皮摩尔/毫克）的结合位点结合。其结合受到LqhαIT（半数抑制浓度IC50 = 80 ± 30皮摩尔）和海葵毒素ATX II（IC50 = 2.5 ± 0.3纳摩尔）的抑制，这表明Lqq III是蟑螂钠通道受体位点3的特异性探针。125I-Lqq III与对昆虫毒性较小的蝎α毒素之间的竞争性结合实验证实了这一点。