Zhu K Y, Clark J M
Department of Entomology, University of Massachusetts, Amherst 01003, USA.
Insect Biochem Mol Biol. 1995 Dec;25(10):1129-38. doi: 10.1016/0965-1748(95)00055-0.
A cDNA encoding acetylcholinesterase (AChE, EC 1.1.1.7) was cloned from a cDNA library constructed from an insecticide-susceptible strain of Colorado potato beetle, Leptinotarsa decemlineata (Say). The complete amino acid sequence of AChE deduced from the cDNA consisted of 29 residues for the putative signal peptide and 600 residues for the mature protein with a predicted molecular weight of 67,994. Northern blot analysis of poly(A) RNA showed an approx 13.1-kb transcript. The mature protein sequence had 57 and 61% of amino acid residues identical to those of Drosophila melanogaster and Anopheles stephensi, respectively, and produced a remarkably similar hydropathy profile when compared to those of the two dipterous species. The three residues (Ser, Glu and His) that putatively form the catalytic triad and the six Cys that form intra-subunit disulfide bonds were completely conserved when compared to the other seven AChEs from a broad range of animal species reported to date. Other properties of the deduced protein of AChE, including molecular weight and amino acid composition, agreed well with those of a previously reported study on the purified AChE from the same insect species. All these features firmly established that the cloned cDNA encodes AChE in Colorado potato beetle.
从由科罗拉多马铃薯甲虫（Leptinotarsa decemlineata (Say)）的一个对杀虫剂敏感的品系构建的cDNA文库中克隆出了一个编码乙酰胆碱酯酶（AChE，EC 1.1.1.7）的cDNA。从该cDNA推导的AChE完整氨基酸序列包括推测的信号肽的29个残基和成熟蛋白的600个残基，预测分子量为67,994。对聚腺苷酸RNA的Northern印迹分析显示有一个约13.1 kb的转录本。成熟蛋白序列分别有57%和61%的氨基酸残基与黑腹果蝇和斯氏按蚊的相同，并且与这两个双翅目物种的相比产生了非常相似的亲水性图谱。与迄今为止报道的来自广泛动物物种的其他七种AChE相比，推测形成催化三联体的三个残基（丝氨酸、谷氨酸和组氨酸）以及形成亚基内二硫键的六个半胱氨酸是完全保守的。AChE推导蛋白的其他特性，包括分子量和氨基酸组成，与先前关于从同一昆虫物种纯化的AChE的研究结果非常吻合。所有这些特征都确凿地证明克隆的cDNA编码科罗拉多马铃薯甲虫中的AChE。
