乙型肝炎病毒感染是全球性公共卫生问题,现有3.5 亿患者受其困扰,能和乙肝病毒表面特异性位点结合并封闭其侵袭肝细胞活性的单克隆抗体和抗体片段是唯一能用于紧急预防的生物制品。本文在前期工作的基础上,将筛选到的抗HBsAg Fab 片段改造成单链抗体(single-chain Fv against HBsAg, HBscFv),分别在大肠杆菌和巴氏毕赤酵母中表达,并对表达产物进行纯化及体内外生物学活性和理化性质鉴定。
采用基因重叠延伸拼接法构建抗HBsAg 单链抗体基因,测序确认后,亚克隆至原核表达载体pQE-40,获得表达质粒pQE-HBscFv,并转入宿主菌E.coli M15[pREP4],获得工程菌M15[pQE-HBscFv];工程菌经IPTG 诱导后,合成大量重组HBscFv,其含量可达菌体总蛋白的31.2%;进一步实验表明,重组HBscFv主要以包涵体的形式存在于细胞质中;将表达质粒pQE-HBscFv 转化有利于二硫键形成的氧化还原系统缺陷型宿主菌E. coli Origami(DE3),产物仍为包涵体;对包涵体进行简单复性后测定复性产物活性,结果表明,重组HBscFv 具有...
【英文摘要】
Hepatitis B virus infection is a worldwide public health problem affecting about 350 million people. Monoclonal antibodies or their fragments are only useful in prevention if they bind to and block surface regions of the virus which are essential for the infection of hepatocytes. The objective of this paper is to generate a single-chain Fv antibody against HBsAg (HBscFv) from a human Fab fragment screened in previous study, and to express the HBscFv in Escherichia coli and Pichia pastoris, and to purify and...