草坪害虫华北大黑鳃金龟幼虫围食膜蛋白Ho-Peritrophin3基因克隆及序列分析

华北大黑鳃金龟是一种重要的草坪害虫,其幼虫中肠围食膜是害虫生物防治的潜在靶标。本研究利用棉铃虫围食膜蛋白多克隆抗体,从已构建的华北大黑鳃金龟中肠cDNA表达文库中筛选得到一个编码围食膜蛋白的cDNA克隆Ho-Peritrophin3,其cDNA长度为1737bp,在polyA末端上游含有1个多聚腺苷酸信号序列AATAAA,最长开放阅读框(ORF)编码528个氨基酸,与华北大黑鳃金龟围食膜蛋白Ho-Peritrophin2的相似性最高,为64.9%。结构域分析表明,Ho-Peritrophin3只含有较少的O-糖基化位点和N-糖基化位点,不含有类粘蛋白结构域,具有5个几丁质结合功能域(chitinbindingdomain,CBD),它们均由6个保守的半胱氨酸残基组成,与Ho-Peritrophin1、Ho-Peritrophin2羧基端的CBD只含有4个半胱氨酸残基明显不同。Ho-Peritrophin3的胰蛋白酶和胰凝乳蛋白酶的作用位点主要位于5个CBD内部,受到其保护,不会被降解;与Ho-Peritrophin1、Ho-Peritrophin2不同的是在第5个CBD下游区域的107个氨基酸中,有36.3%的氨基酸属于胰蛋白酶和胰凝乳蛋白酶的酶切位点。

Molecular cloning and sequencing of cDNAs of the novel protein Ho-Peritrophin3 from the peritrophic matrix of Holotrichia oblita,a turfgrass pest

Holotrichia oblita is an important turfgrass pest,whose peritrophic matrix is a potential target for biocontrol of pest insects.The peritrophic matrix proteins of H.oblita were studied by screening with a PM protein polyclonal antiserum from Helicoverpa armigera.One positive cDNA clone named Ho-Peritrophin3,with a size of 1 737 bp and a polyadenylation signal of AATAAA upstream of the polyA tail,was screened and sequenced from the library.The longest open reading frame of Ho-Peritrophin3 coded for 528 amino...