鼠抗人纤维蛋白抗体单链Fv片段的人源化分子设计

产生免疫原性的残基都是位于蛋白表面的暴露残基,为了消除鼠抗体对人的免疫原性,利用表面再塑方法对本室克隆的鼠抗人纤维蛋白抗体单链Fv片断进行了人源化分子设计。首先确定了鼠及人Fv表面残基,在此基础上分析了鼠与人Fv间表面残基的差异,将有差异的鼠表面残基换成人的。提出了残基最高频率人源化及最相似链人源化两种人源化方案。人源化后鼠抗人纤维蛋白抗体单链Fv的结构经Profile-3D验证是合理的,置换的表面残基溶液可及性未变,且未影响CDRs的结构,应不会影响与纤维蛋白的亲和力,为鼠抗体人源化实验研究奠定了基础。

Humanization Molecular Design of the Single -Chain Fv Fragment of Murine Antibody Against Human Fibrin

Immunogenicity of murine antibody variable regions originates with the surface residues. In order to eliminating the immunogenicity in human, humanization of the single - chain Fv fragment of murine antibody against human fibrin which cloned by the phage display in the lab, was designed by resurfacing the molecule. First , the surface residues of the Fv which may induced the immunogenicity were determined. Then the differences between the surface residues of murine and human antibody Fv fragments were analyzed, and the different surface residues of the murine antibody Fv against human fibrin studied in the paper were replaced by those from human. In the study, two humanization strategies, the most similar chain surface humanization and the most frequent surface humanization, were reported. Both of the three -dimensional structures of the humanized murine Fv fragment designed by the two strategies were proved reasonable by Profile -3D program. The analyses showed that the solution accessible properties of the mutated surface residues of the humanized Fv fragment were not changed. In addi-tion, the CDRs structures of the two humanized Fv were not affected by the residue changes, so the affinity for fibrin of them may not be declined.