基于表面重塑方法的抗体HAb18可变区人源化设计

Humanization Design of Antibody HAb18 Based on Variable Domain Resurfaciog

在分析抗体空间结构特点和残基间相互作用基础上,利用计算机辅助的分子设计和表面残基替换法进行鼠源抗体人源化设计。在抗体同源模建的基础上,利用序列分析和结构分析确定鼠源抗体可变区中外露的非人样差异残基,参考分子内、间氢键相互作用,最终选定将要突变的残基位点。使用这种方法对一株抗人肝癌细胞的单克隆抗体HAb18进行了人源化改造设计,并将候选位点分为三类,以便于在实验中依次突变,寻找降低鼠源抗体免疫原性和保持其生物功能之间适宜的平衡点。结果表明表面重塑方法可以有效地减少抗体人源化设计中CDR空间构象的变化,维持抗体生物活性,为试验提供有力的理论依据。

To perform a design of humanizing murine antibody with the method of residue replacement based on analyzing of antibody spatial structure and interaction among residues by means of computer assisted molecule design, identification of the surface exposed non-human like residues of variable region of mAb and calculation of inter-molecular and intra-moleeular hydrogen bond interaction by sequence and structure analysis in terms of the ho- mology modeled variable region of mAb, were used to determine the residues that need to be mutated to their human counterpart. The method is applied to the humanization design of the monoelonal antibodies HAbl8 against human bepatoma cell. The candidate mutation sites were put into three categories in experiment for maintaining an appropriate balance between the biological function and reduced immunogenieity. Humanization design by variable domain resurfaeing might effectively reduce variation of spatial conformation of CDR and sustain the bioaetivity of antibody. So the method can provide an important theoretical evidence for next experiment.