用单价STV制备单分子蛋白质-DNA复合物的研究  

Studies on Preparation of Single Protein-DNA Conjugates Using Monovalent Streptavidin

作　　者：何珊珊[1] 侯彩玲[1] 代田纯 杨秋萍[1] 王志民[1] 

机构地区：[1]上海交通大学农业与生物学院,上海200240

出　　处：《上海交通大学学报（农业科学版）》2017年第6期39-44,共6页Journal of Shanghai Jiaotong University(Agricultural Science)

基　　金：上海交通大学重大项目及团队培育基金(X199775)

摘　　要：将生物素结合位点失活的链霉亲和素(streptavidin,STV)变异体变性后的亚基与野生型STV变性后的亚基以摩尔比3∶1的比例混合,然后重折叠复性,镍柱层析分离得到只有一个有活性生物素结合位点的突变体STV,即单价STV。将单价STV与500bp一端生物素标记的双链DNA(biotin-DNA)按不同摩尔比混合孵育,探讨使用单价STV制备1STV-1DNA复合物的可行性,并筛选制备1STV-1DNA复合物的最佳混合摩尔比。结果表明,在所用的摩尔比梯度中,单价STV与biotin-DNA混合的最佳摩尔比为1∶1,与使用野生型STV制备方法相比,使用单价STV更为简便、高效,为单分子DNA操纵、单分子DNA-蛋白质相互作用研究以及单分子DNA芯片的制备等提供了便捷的方法。Monovalent streptavidin（STV）was prepared through renaturation of denatured mutant with inactivated biotin binding sites and wild-type STV mixture by a molar ratio of 3 ： 1, followed by purification through a nickel-affinity column as previously reported. Biotinylated DNA of 500 bp was incubated with monovavent STV at different molar ratios to screen the best ratio for preparation of 1STV- 1DNA single-molecule conjugates. Results showed that, among the molar ratio gradients selected in this study, 1 ： 1 ratio of STV to DNA was optimal. This single protein-DNA conjugate method using monovalent STV was significantly superior to that using wild-type STV, providing a convenient and highly efficient approach for applications in the study of DNA manipulation, DNA-protein interaction and fabrication of DNA chips at the single molecule level.

关 键 词：单价链霉亲和素 单分子操纵 STV-DNA复合物 

分 类 号：Q512[生物学—生物化学]