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目的 观察抗体分子通过丝状噬菌体主要外壳蛋白Ⅷ（ｃｐⅧ）和次要外壳蛋白Ⅲ（ｃｐⅧ）在噬菌体表面呈现效果的差异。方法 分别构建通过ｃｐⅧ或ｃｐⅧ展示抗乙肝表面抗原（ＨＢｓ）Ｆａｂ、ＳｃＦＶ和抗角蛋白（Ｋｅｒ）Ｆａｂ的表达载体，制备噬菌体抗体，比较其抗原结合活性和Ｆａｂ呈现水平。用多种方法尝试提高ｃｐⅧ 介导的噬菌体展示效果。结果ｃｐⅧ对不同特异性抗体Ｆａｂ段和不同形式的小分子抗体（Ｆａｂ和ＳｃＦｖ）的展示效果均低于ｃｐⅧ的展示，增加 ｃｐⅧ-Ｆａｂ对野生型 ｃｐⅧ的表达比例、试用不同菌株、在Ｆａｂ和ｃｐⅧ之间插入间隔序列及换用控制更为严密的启动子等措施，均未能改善ｃｐⅧ介导的噬菌体展示。结论 以前所报道的通过ｃｐⅧ多价展示Ｆａｂ段不是普遍存在的现象，对有些抗体基因不能达到多价展示。
OBJECTIVE: To observe the difference of phage display of antibody molecules between the major coat protein Ⅷ (cpⅧ) and the minor coat protein Ⅲ (cpⅧ) of filamentous phage. Methods The expression vectors of Fab, ScFV and Ker Fab of HBs were displayed by cpⅧ or cpⅧ, respectively. The phage antibodies were prepared and the antigen - binding activity and the level of Fab were compared. Several approaches have been used to improve cpⅧ-mediated phage display. Results The display of cpⅧ against different specific antibody Fab fragments and different forms of small molecule antibodies (Fab and ScFv) was lower than that of cpⅧ and increased the ratio of cpⅧ-Fab to wild-type cpⅧ. Different strains were tested in Fab and cpⅧ inserted between the spacer sequence and switch to a more stringent promoter and other measures, failed to improve cpⅧ-mediated phage display. Conclusion The previously reported phenomenon that the Fab fragment is multivalently expressed by cpⅧ is not a ubiquitous phenomenon and some antibody genes can not achieve multivalent display.