Rajagopal Soumitra, Sudarsan Narasimhan, Nickerson Kenneth W
School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588-0666, USA.
Appl Environ Microbiol. 2002 Aug;68(8):4117-21. doi: 10.1128/AEM.68.8.4117-4121.2002.
We studied the hypersensitivity of clpP and clpB mutants of Escherichia coli to sodium dodecyl sulfate (SDS). Both wild-type E. coli MC4100 and lon mutants grew in the presence of 10% SDS, whereas isogenic clpP and clpB single mutants could not grow above 0.5% SDS and clpA and clpX single mutants could not grow above 5.0% SDS. For wild-type E. coli, cellular ClpP levels as determined by Western immunoblot analysis increased ca. sixfold as the levels of added SDS increased from 0 to 2%. Capsular colanic acid, measured as uronic acid, increased ca. sixfold as the levels of added SDS increased from 2 to 10%. Based on these findings, 3 of the 19 previously identified SDS shock proteins (M. Adamowicz, P. M. Kelley, and K. W. Nickerson, J. Bacteriol. 173:229-233, 1991) are tentatively identified as ClpP, ClpX, and ClpB.
我们研究了大肠杆菌的clpP和clpB突变体对十二烷基硫酸钠（SDS）的超敏反应。野生型大肠杆菌MC4100和lon突变体在10% SDS存在的情况下能够生长，而同源的clpP和clpB单突变体在SDS浓度高于0.5%时无法生长，clpA和clpX单突变体在SDS浓度高于5.0%时无法生长。对于野生型大肠杆菌，通过蛋白质免疫印迹分析测定的细胞ClpP水平，随着添加的SDS水平从0%增加到2%，大约增加了六倍。以糖醛酸衡量的荚膜多糖酸，随着添加的SDS水平从2%增加到10%，大约增加了六倍。基于这些发现，在先前鉴定的19种SDS休克蛋白中（M. Adamowicz、P. M. Kelley和K. W. Nickerson，《细菌学杂志》173:229 - 233，1991），暂时确定其中3种为ClpP、ClpX和ClpB。
