Murphey-Corb M, Murray M L
J Bacteriol. 1979 Sep;139(3):817-23. doi: 10.1128/jb.139.3.817-823.1979.
Plasmid-to-chromosome ratios in Enterobacteriaceae, upon interruption of protein synthesis by chloramphenicol, are either conserved or increased when measured by dye buoyant density centrifugation. We have found, on the other hand, that the effect of inhibition of protein synthesis on the amount of covalently closed circular deoxyribonucleic acid visualized by this method in two strains of Streptococcus faecalis appears to differ from these established systems. A three- to sixfold decrease in covalently closed circular deoxyribonucleic acid was observed when lysates of chloramphenicol-treated cultures were submitted to dye buoyant density centrifugation. A loss of covalently closed circular deoxyribonucleic acid was also evident from electrophoretic profiles of these lysates. Several conditions which could account for the apparent loss of covalently closed circular deoxyribonucleic acid upon inhibition of protein synthesis are discussed.
在肠杆菌科细菌中，当用氯霉素中断蛋白质合成后，通过染料浮力密度离心法测定时，质粒与染色体的比率要么保持不变，要么增加。另一方面，我们发现，在两株粪链球菌中，用这种方法观察到的蛋白质合成抑制对共价闭合环状脱氧核糖核酸量的影响似乎与这些已确立的系统不同。当氯霉素处理的培养物裂解物进行染料浮力密度离心时，观察到共价闭合环状脱氧核糖核酸减少了三到六倍。这些裂解物的电泳图谱也明显显示出共价闭合环状脱氧核糖核酸的损失。本文讨论了几种可能解释蛋白质合成受抑制后共价闭合环状脱氧核糖核酸明显损失的情况。
