RGD-蜘蛛拖丝蛋白聚合物的生物合成与纯化

蜘蛛拖丝是自然界性能最好的蛋白质纤维之一 ,其独特的机械性能 ,良好的生物相容性和缓慢的可降解性 ,作为生物材料在组织工程领域有着潜在的应用前景。本文根据蜘蛛拖丝蛋白序列高度重复的特点 ,引入与细胞黏附有关的精氨酸 甘氨酸 天冬氨酸 (RGD)三肽 ,化学合成RGD 蜘蛛拖丝蛋白基因单体 ,通过头尾相连倍加构建策略 ,首次得到RGD 蜘蛛拖丝蛋白基因 8聚体和 16聚体。分别将这两种多聚体与原核高效表达载体 pET 30a( )连接 ,转化大肠杆菌BL2 1(DE3) pLysS ,用IPTG诱导表达。SDS PAGE图谱显示表达产物分子量分别为 35KD和 6 0KD ,与理论值基本相吻合 ;蛋白质印迹分析这两种表达产物均显示特异性。文中对表达产物的纯化方法进行了初步的摸索。

Biological Synthesis and Purification of Spider Dragline Silk Protein Polymers Containing RGD Three Peptide

Spider dragline silk is one of most perfect fibrous proteins in nature. As biomaterials, it has a wide application in tissue engineering due to its unique mechanical properties, good biocompatibility, slow degradation. In this paper, based on the highly repetitive sequence of spider dragline silk and with the introduced RGD peptide codons which involve cell adhesion, the DNA monomer sequence encoding RGD-spider dragline silk was synthesized, and then was used to construct the multimers by the strategy of "head to tail"; the multimers were ligated into prokaryotic expression vector pET-30a, and then the B121 (DE3) pLyS, were transformed the expression of recombinant protein was induced by the addition of IPTG. SDS-PAGE analysis shows that the molecular weight of products expressed here are 35KD and 60KD respectively in agreement with the desired. Western assay was used for determining the specification of products. Further, the purification process was groped for the producing of large quantity of synthetic proteins through high density fermentation.