期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1978
卷号:75
期号:5
页码:2483-2487
DOI:10.1073/pnas.75.5.2483
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Colicin K causes a rapid and drastic reduction of the membrane potential of Escherichia coli cells, as measured by the uptake of the lipophilic cation triphenylmethylphosphonium. The colicin causes no major changes in the pH gradient, as measured by the uptake of butyric acid. The decrease in membrane potential following addition of colicin K to the cells is a prompt response that parallels or precedes known physiological effects such as efflux of accumulated substrates. Hence the loss of membrane potential qualifies as the primary action by which the colicin uncouples membrane-associated function from respiration. Certain peculiarities of bacterial cells pretreated with EDTA in their response to uncoupling agents and lipophilic ions are described.