人多瘤病毒BK株VP1的C端阳电荷残基对病毒样颗粒形成的影响  

Positively Charged Amino Acid Residues of VP1 Capsid Protein of Human Polyomavirus BK Influence on the Formation of Virus-like Particles Generated by Recombinant Baculoviruses

作　　者：柯昌文[1] 李天成 武田直和 

机构地区：[1]广东省疾病预防控制中心,广东广州510300 [2]日本国立感染症研究所,日本东京2080011

出　　处：《中国病毒学》2005年第1期20-23,共4页Virologica Sinica

摘　　要：VP1是人多瘤病毒BK株的主要结构蛋白,使用重组杆状病毒表达系统在体外表达 VP1 可以形成病毒样颗粒(VLP)。为了探讨VP1的C末端阳电荷残基R 281, R 285, K 288, R 290, R 292, K 293, R 294,和 K297 对VLP形成和其结合DNA的影响,我们分别改变将阳电荷残基变成丙氨酸,然后表达 VP1 蛋白。结果发现用丙氨酸替代K 288,R 290,R 292,K 293,R 294后仍能形成VLP, 但与野毒株相比,在 VLP分泌以及衣壳蛋白与细胞DNA的结合方面有差异。有趣的是,R 281被丙氨酸取代后仅在细胞中形成少量的 VLP,而 R 285 被丙氨酸取代后不能形成VLP。该研究证实阳电荷氨基酸残基 R 281 和 R 285 是形成 VLP所必须的,K 288、R 290、R 292、K 293、R 294和K 297则影响VLP和DNA的结合。VP1 is the major structural protein of the human polyomavirus BK and can be used for the generation of virus-like particles (VLP) in vitro by using recombinant baculoviruses. To determine the role of positively charged residues R-281, R-285, K-288, R-290, R-292, K-293, R-294, and K297 at the C terminal of VP1 in VLP formation and DNA binding, we separately changed the residue to alanine, and expressed VP1 protein. The results showed that substitution of K-288, R-290, R-292, K-293, R-294, and K297 with alaninecan still form VLP, but compared with wild type there were some differences in releasing VLP into culture medium and binding between major capsid proteins and cellular DNA . Interestingly,after substituting R-281 and R-285 with alanine, a few VLP in cell but no VLP were detected respectively. This study provides evidence that positively charged residues R-281 and R-285 are necessary to form VLP and the others can influence the binding between major capsid proteins and cellular DNA.

关 键 词：人多瘤病毒BK株 病毒样颗粒 杆状病毒表达 精氨酸 

分 类 号：R373[医药卫生—病原生物学]