Wang P, Hammer D A, Granados R R
Department of Entomology, Cornell University, Ithaca, New York 14853.
J Gen Virol. 1994 Aug;75 ( Pt 8):1961-7. doi: 10.1099/0022-1317-75-8-1961.
Enhancin, an infectivity-enhancing protein from Trichoplusia ni granulosis virus (TnGV) was tested for its ability to increase Autographa californica multiple nucleocapsid nuclear polyhedrosis virus (AcMNPV) infection in the larvae of four lepidopteran insects. Enhancin increased the mortality of AcMNPV infection in all the four insect species tested. Peritrophic membrane (PM) assays showed altered protein profiles in PMs treated with enhancin in all the four species. This supports the hypothesis that enhancin affects virus infection by altering the structural integrity of the PMs. The binding of enhancin to the midgut brush border membranes (BBMs) was determined and specific binding sites were found on the BBM of Pseudaletia unipuncta. No specific binding sites were found on the BBMs of T. ni, Helicoverpa zea or Spodoptera exigua. Therefore, specific binding of enhancin to the midgut cell membrane may not be necessary for the enhancement of baculovirus infection in insects.
增效蛋白是一种来自粉纹夜蛾颗粒体病毒（TnGV）的增强感染力的蛋白质，对其在四种鳞翅目昆虫幼虫中增强苜蓿银纹夜蛾多粒包埋核型多角体病毒（AcMNPV）感染力的能力进行了测试。增效蛋白增加了所测试的所有四种昆虫物种中AcMNPV感染的死亡率。围食膜（PM）分析表明，在所有四个物种中，用增效蛋白处理的围食膜中的蛋白质谱发生了改变。这支持了增效蛋白通过改变围食膜的结构完整性来影响病毒感染的假说。测定了增效蛋白与中肠刷状缘膜（BBM）的结合情况，并在小地老虎的中肠刷状缘膜上发现了特异性结合位点。在粉纹夜蛾、棉铃虫或甜菜夜蛾的中肠刷状缘膜上未发现特异性结合位点。因此，增效蛋白与中肠细胞膜的特异性结合对于增强杆状病毒在昆虫中的感染可能不是必需的。
