EVIDENCE FOR A RING STRUCTURE OF POLYOMA VIRUS DNA
EVIDENCE FOR A RING STRUCTURE OF POLYOMA VIRUS DNA
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DOI：
10.1073/pnas.50.2.236
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发表时间：
1963-01-01
影响因子：
11.1
通讯作者：
VOGT, M
中科院分区：
文献类型：
--
作者：
DULBECCO, R;VOGT, M
结果。-简而言之，获得了以下结果。(1)PY DNA总是以快带（F）和慢带（S）沉淀。F和S组分在各种条件下都是稳定的;两者都具有感染性。(2)在甲基化白蛋白柱中，S组分在比F组分更高的盐浓度下洗脱。(3)通过密度梯度平衡离心进行以下观察。在pH7.5时，F组分和S组分形成的条带密度相同，宽度相差不大;在pH11.8时，大部分F组分具有天然DNA的密度，而S组分具有变性DNA的密度。在pH 12.5时，两种组分均变性; S组分形成较宽的条带。(4)在pH 12.5的带沉降中，F组分的沉降速度比pH 7.5时快约2.5倍;中和和退火后，它重新获得了原始的沉降特性。相反，S组分在pH 12.5时迁移，其速度与pH 7.5时大致相同。(5)在pH 12.5下处理后，F组分的感染性增加数倍，然后中和;在此处理后，S组分的感染性丧失。(6)胰腺DNA酶将F成分转化为S成分，失去感染性。转化的动力学是不寻常的，因为它是一级动力学。这些结果表明，在不同的236个多瘤病毒DNA分子中，
Results.-In brief, the following results were obtained.(1) PY DNA always sediments in two bands, a fast one (F) anda slow one (S). TheF and S components are stable under a variety of conditions; bothare infectious.(2) In the column of methylated albumin the Scomponent is eluted at higher salt concentration than the F component.(3) The following observations were made by density gradient equilibrium centrifugation. At pH 7.5 the bands formed by theF and by the S component have the same density and do not differ greatly in width; at pH 11.8 most ofthe F component has the density of native DNA, whereas the S component has the density of denatured DNA. At pH 12.5 both components are denatured; the S component forms a wider band.(4) In band sedimentation at pH 12.5 the F component sediments about 2.5 times faster than at pH 7.5; after neutralization and annealing it reacquires the original sedimentation characteristics. The S component, on the contrary, migrates at pH 12.5, about the same speed as at pH 7.5.(5) The infectivity of the F component is increased several times after treatment at pH 12.5 followed by neutralization; the infectivity of the S component is lost after this treatment.(6) Pancreatic DNAase converts the F component into the S component, with loss of infectivity. The kineticsof conversion is unusual, since it is of first order. These results show that molecules of polyoma virus DNA in different 236