Zibert A, Selinka H C, Elroy-Stein O, Wimmer E
Department of Microbiology, State University of New York, Stony Brook 11794.
Virus Res. 1992 Sep 1;25(1-2):51-61. doi: 10.1016/0168-1702(92)90099-u.
By means of deleting a C-terminal portion of the open reading frame of the poliovirus receptor cDNA, and by vaccinia virus-mediated overexpression we have produced a protein corresponding to the first two N-terminal Ig-like domains of the poliovirus receptor. This protein that lacked the third Ig-like domain, the transmembrane region and most of the intracellular C-terminal tail was detected in the medium of vaccinia virus infected cells. The properties of the truncated PVR cDNA were further characterized by in vitro translation and modification. The molecular weight of the unmodified protein was found to be 27 kDa; translation in the presence of dog pancreas microsomes led to an increase in molecular weights which we attribute to N-glycosylation. Upon incubation with poliovirus at 37 degrees C, the vaccinia-virus generated protein specifically reduced infectivity of poliovirus. Sucrose gradients of poliovirus particles derived after incubation with the protein showed the induction of a slower sedimenting particle (135S). Our experiments suggest that the two N-terminal domains of the poliovirus receptor in soluble form are sufficient for the conversion of poliovirus into a non-infectious particle.
通过删除脊髓灰质炎病毒受体cDNA开放阅读框的C末端部分，并通过痘苗病毒介导的过表达，我们产生了一种与脊髓灰质炎病毒受体前两个N末端Ig样结构域相对应的蛋白质。这种缺乏第三个Ig样结构域、跨膜区域和大部分细胞内C末端尾巴的蛋白质在痘苗病毒感染细胞的培养基中被检测到。通过体外翻译和修饰进一步表征了截短的PVR cDNA的特性。未修饰蛋白质的分子量为27 kDa；在狗胰腺微粒体存在下进行翻译导致分子量增加，我们将其归因于N-糖基化。在37℃下与脊髓灰质炎病毒孵育后，痘苗病毒产生的蛋白质特异性降低了脊髓灰质炎病毒的感染性。与该蛋白质孵育后得到的脊髓灰质炎病毒颗粒的蔗糖梯度显示诱导出沉降较慢的颗粒（135S）。我们的实验表明，可溶性形式的脊髓灰质炎病毒受体的两个N末端结构域足以将脊髓灰质炎病毒转化为无感染性的颗粒。
