Green M H, Miller H I, Hendler S
Proc Natl Acad Sci U S A. 1971 May;68(5):1032-6. doi: 10.1073/pnas.68.5.1032.
A complex containing polyoma (py) DNA and protein (py complex) was isolated from polyoma-infected mouse-cell cultures. The complex sedimented unimodally at about 55 S. When labeled for long periods (2-3 hr) between 20 and 40 hr after infection, most of the [(3)H]DNA in the py complex was in the form of covalently closed, circular polyoma DNA (component I). When labeled for 5 min, the [(3)H]DNA in the py complex was nicked in one or both of the strands, as shown by alkaline sucrose gradient centrifugation. Under all conditions studied, no free py DNA was extracted from mouse cells by the two methods described.
从多瘤病毒感染的小鼠细胞培养物中分离出一种包含多瘤病毒(py)DNA和蛋白质的复合物(py复合物)。该复合物在约55 S处呈单峰沉降。在感染后20至40小时之间进行长时间(2 - 3小时)标记时,py复合物中的大部分[³H]DNA呈共价闭合的环状多瘤病毒DNA形式(组分I)。当进行5分钟标记时,如碱性蔗糖梯度离心所示,py复合物中的[³H]DNA在一条或两条链上有切口。在所研究的所有条件下,通过所述的两种方法均未从小鼠细胞中提取到游离的py DNA。