利用pⅧ展示系统改进噬菌体抗体芯片

Improving Phage Antibody Chip by pⅧ Display System

将展示单链抗体的重组噬菌体与羧基终止的硅片偶联,制成噬菌体抗体芯片,可用于检测多类蛋白质和蛋白质组.通常抗体被展示于噬菌体外壳蛋白pⅢ上,由此制备的芯片灵敏度和信噪比较低.我们选用凝血酶特异的单链抗体为代表,比较了pⅢ展示系统和pⅧ展示系统制成芯片的检测效果.由于pⅧ展示系统的融合蛋白拷贝数多,所受空间位阻小,大幅度提高了噬菌体抗体芯片的灵敏度和信噪比,有望用于制备新型蛋白质芯片.

Phage antibody chips, prepared by coupling the recombinant phage displaying scFv with carboxyl-terminated silicon, can be applied in detecting proteins and proteomes. In previous work, we immobilized phages displaying scFv on the coat protein pⅢ on silicon surface as model chips. To improve the sensitivity and the ratio of signal to noise, in this work, scFv specific binding to thrombin was displayed by pⅧ display system, which is the major coat protein on the phage. As the results of changing from pⅢ to pⅧ display, the sensitivity and the ratio of signal to noise of chips were enhanced prominently, due to the increase of the copy number and the decrease of steric hindrance. It is concluded that scFv fused to the coat protein pⅧ is a promising candidate for the preparation of novel protein chips.