Osborn J E, Robertson S M, Padgett B L, ZuRhein G M, Walker D L, Weisblum B
J Virol. 1974 Mar;13(3):614-22. doi: 10.1128/JVI.13.3.614-622.1974.
JC virus was found to have a buoyant density of 1.20 g/cm(3) in linear sucrose-D(2)O and 1.35 g/cm(3) in cesium chloride isopycnic gradients. DNA extracted either from JC-infected cultures or from gradient-purified virions occupied a dense position relative to linear DNA in cesium chloride/ethidium bromide gradients, and the circular configuration of the extracted DNA was confirmed by electron microscopy, with a measured molecular weight of 2.93 x 10(6). DNA from BK virus was similarly prepared and compared to JC and to an SV40 DNA standard by digestion with restriction endonuclease preparations from Haemophilus influenzae, Haemophilus parainfluenzae, and Escherichia coli. Digests were electrophoretically analyzed on gradient polyacrylamide slab gels or agarose gels, and the three viruses were found to have distinctly different cleavage patterns by this form of analysis: JC and BK viruses were almost entirely different from SV40 and significantly different from each other. Thus, JC and BK human papovaviruses appear to be discrete new members of the papovavirus group, rather than SV40 variants.
在蔗糖 - D₂O线性梯度中，JC病毒的浮力密度为1.20 g/cm³，在氯化铯等密度梯度中为1.35 g/cm³。从感染JC的培养物或梯度纯化的病毒粒子中提取的DNA，在氯化铯/溴化乙锭梯度中相对于线性DNA占据致密位置，并且通过电子显微镜确认了提取DNA的环状结构，其测得的分子量为2.93×10⁶。用来自流感嗜血杆菌、副流感嗜血杆菌和大肠杆菌的限制性内切酶制剂消化BK病毒的DNA，以类似方式制备并与JC病毒的DNA以及SV40 DNA标准品进行比较。消化产物在梯度聚丙烯酰胺平板凝胶或琼脂糖凝胶上进行电泳分析，通过这种分析形式发现这三种病毒具有明显不同的切割模式：JC病毒和BK病毒几乎与SV40完全不同，且彼此之间也有显著差异。因此，JC病毒和BK人乳头瘤多瘤病毒似乎是乳头瘤多瘤病毒组中不同的新成员，而非SV40变体。
