haFGF Mutant Site-directed Modified by PEG Huang Zhifeng, Zheng Qing*, Su Zhijian, Wu Xiaoping, Huang Yadong, Xu Hua, Zhao Wen, Li Xiaokun, Qu Hongyan, Yu Pingye (Biopharmaceutical R&D Center of Jinan University, Guangzhou 510630) Abstract mPEG5000 was site-directed coupling to the 31st Cysteine residue of human acid fibroblast growth factor mutant, of which the 98th and the 132nd cysteine residue was replaced by Serine residue. The modified reaction was conducted at 25℃ for 4h. The optimal mol ratio of maleimide-6-aminocaproyl-mPEG5000 ester vs haFGFSer98,132 was 30/1. The modified products were analysed by reversed-phase HPLC and SDS-PAGE. The result indicated that the modification rate was up to 30% and the apparent molecular weight of the PEG-haFGF conjugate was 27kD. The final product PEG-haFGF was purified to homogeneity by Heparin affinity chromatography. The activity of the purified PEG-haFGF remained 55.53% of the activity of the haFGF mutant. Key words Human acid fibroblast growth factor mutant, PEG, Site-directed modification 聚乙二醇定点修饰haFGF突变体 黄志锋 郑 青* 苏志坚 吴晓萍 黄亚东 许 华 赵 文 李校坤 曲红艳 于平野 (暨南大学药学院医药生物技术研究开发中心 广州 510632) 摘 要 将 mPEG5000 偶联到人酸性成纤维细胞生长因子(haFGF)突变体的第 31 位 cys 残基上，对 haFGFSer98,132 突变体进行定点修饰，修饰反应条件以马来酰亚胺-6-氨基己酸-mPEG5000 酯和 aFGFSer98,132 摩尔比 30/1、反应温度 25℃、反应时间 4h 为佳。经反相高效液相色谱和 SDS-PAGE 凝胶电泳分析，修饰率达到 30%以上，修饰后产物表观分子量为 27kD，修饰产物的比活性保留 55.53%。 关键词 人酸性成纤维细胞生长因子突变体 聚乙二醇 定点修饰 黄志锋 男，24岁，硕士生，现从事蛋白质结构和修饰研究。 *联系人，E-mail:qz01cn@163.com 广东省自然科学基金(010424)、国家863计划(2001AA215131，2002AA2Z3318)资助项目 2003-09-22收稿，2004-02-20接受 (PDF全文下载c04082)