新烟碱类杀虫剂选择作用的分子机理

Molecular Mechanism of Selectivities of Neonicotinoid Insecticides

新烟碱类杀虫剂的选择作用可以从昆虫和脊椎动物烟碱型乙酰胆碱受体(nAChR)的特点、新烟碱类杀虫剂同nAChR天然激动剂乙酰胆碱(acetylcholine,ACh)的分子特点以及激动剂和受体之间互作的分子机制等方面加以说明。激动剂的分子特点研究表明,新烟碱类杀虫剂和ACh药效基团在静电性上分别显示负电性和正电性。用昆虫α亚基和脊椎动物β亚基组成的杂合受体同激动剂相互作用的研究,主要集中在受体亚基上不同氨基酸残基与不同激动剂结合电生理效应的特点上。研究结果发现,ACh结合部位D环上的碱性氨基酸对新烟碱类杀虫剂选择性的作用尤其明显,同时C环上YXCC模序也引起了大家的注意,而吡虫啉结合部位的芳香氨基酸残基有可能在稳定激动剂四氢咪唑环部分上起作用。乙酰胆碱结合蛋白的晶体结构帮助人们进一步认识了D环上碱性氨基酸残基在新烟碱类选择机制上的作用。

The selectivity of neonicotinoids between insects and mammalian can be elucidated by the character of nAChR, the molecular characteristic of acetylcholine （ACh）, the natural atagonist of nAChR and the molecular mechanism of atagonist and its ligand. Study on molecular characters of atagonist indicated that neonicotinoids insecticides and the active pharmaceutical group displayed electro-negative and electro-positive, and study on the interaction between atagonist and nAChR at the complex of α subunit of insect and β subunit of mammalian indicated that the effect of basic aminoacid in D ring of binding location of ACh is very obvious, and the YXCC in C ring of binding location also attracted the attention too. Tthe aromatic aminoacid residue of binding site for imidacloprid acted positive effect in stabilizing the interaction between atagonist and tetrahydroimidazole. The crystal structure of binding protein of acetylcholine can help us to understand the role of basic aminoacid in D ring of binding location of ACh in the selectivity of neonicotinoid insecticides.