Vílchez Susana, Jacoby Juliette, Ellar David J
Department of Biochemistry, Cambridge University, Cambridge, United Kingdom.
Appl Environ Microbiol. 2004 Nov;70(11):6587-94. doi: 10.1128/AEM.70.11.6587-6594.2004.
The successful use of Bacillus thuringiensis insecticidal toxins to control agricultural pests could be undermined by the evolution of insect resistance. Under selection pressure in the laboratory, a number of insects have gained resistance to the toxins, and several cases of resistance in the diamondback moth have been reported from the field. The use of protein engineering to develop novel toxins active against resistant insects could offer a solution to this problem. The display of proteins on the surface of phages has been shown to be a powerful technology to search for proteins with new characteristics from combinatorial libraries. However, this potential of phage display to develop Cry toxins with new binding properties and new target specificities has hitherto not been realized because of the failure of displayed Cry toxins to bind their natural receptors. In this work we describe the construction of a display system in which the Cry1Ac toxin is fused to the amino terminus of the capsid protein D of bacteriophage lambda. The resultant phage was viable and infectious, and the displayed toxin interacted successfully with its natural receptor.
苏云金芽孢杆菌杀虫毒素用于控制农业害虫的成功应用可能会因昆虫产生抗性而受到影响。在实验室的选择压力下，一些昆虫已对这些毒素产生抗性，并且已从田间报道了小菜蛾的几起抗性案例。利用蛋白质工程开发对抗性昆虫具有活性的新型毒素可能为解决这一问题提供一种方法。噬菌体表面展示蛋白质已被证明是一种从组合文库中筛选具有新特性蛋白质的强大技术。然而，由于展示的Cry毒素无法结合其天然受体，噬菌体展示开发具有新结合特性和新靶标特异性的Cry毒素的这种潜力迄今尚未实现。在这项工作中，我们描述了一种展示系统的构建，其中Cry1Ac毒素与噬菌体λ衣壳蛋白D的氨基末端融合。所得噬菌体具有活力且具有感染性，并且展示的毒素与其天然受体成功相互作用。
