Krauss M R, Gourlie B B, Bayne M L, Benbow R M
J Virol. 1984 Feb;49(2):333-42. doi: 10.1128/JVI.49.2.333-342.1984.
Polyomavirus minichromosomes were isolated and fractionated as described previously (B. B. Gourlie, M. R. Krauss, A. J. Buckler-White, R. M. Benbow, and V. Pigiet, J. Virol. 38:805-814, 1981). Specific assays for DNA topoisomerase II and DNA ligase activity were carried out on each fraction. The enzymatic activity in each fraction was determined by quantitative electron microscopy and compared with the number of replicative intermediate and total polyomavirus DNA molecules in each fraction. DNA topoisomerase II activity cosedimented with polyomavirus replicative intermediate minichromosomes. DNA ligase activity cosedimented with mature polyomavirus minichromosomes.
多瘤病毒微型染色体按照先前描述的方法（B. B. 古利、M. R. 克劳斯、A. J. 巴克勒 - 怀特、R. M. 本博和V. 皮吉特，《病毒学杂志》38:805 - 814, 1981）进行分离和分级分离。对每个级分进行了DNA拓扑异构酶II和DNA连接酶活性的特异性测定。通过定量电子显微镜测定每个级分中的酶活性，并与每个级分中复制中间体和多瘤病毒DNA分子总数进行比较。DNA拓扑异构酶II活性与多瘤病毒复制中间体微型染色体共同沉降。DNA连接酶活性与成熟的多瘤病毒微型染色体共同沉降。
