Skip to main content
Article thumbnail
Location of Repository

Effects of Colicins E1 and K on Permeability to Magnesium and Cobaltous Ions

By Joan E. Lusk and David L. Nelson


The energy-dependent exchange of intracellular Mg2+ with extracellular Mg2+ or Co2+ is inhibited by colicin E1 and, less strongly, by colicin K. Treatment with either colicin causes a net loss of intracellular Mg2+. This loss begins immediately in cells treated with colicin E1, but in colicin K-treated cells the onset of Mg2+ loss is delayed 1 to 10 min, depending upon the temperature and the multiplicity of colicin K. Both colicins differ from chemical inhibitors of energy-yielding metabolism; energy poisons block transport of Mg2+ and Co2+, but both colicins increase passive permeability to Mg2+ and Co2+. Inhibitors of energy-yielding metabolism (and of Mg2+ exchange) block the initiation of Mg2+ loss by either colicin, but do not stop colicin-promoted efflux once it has begun. Colicin E1 added before colicin K prevents the more rapid Mg2+ efflux characteristic of colicin K-treated cells. Quantitative comparisons of the effects of colicins E1 and K upon permeability to Mg2+ and Co2+ lead us to conclude that the two colicins are not identical in their mode of action

Topics: Physiology and Metabolism
Year: 1972
OAI identifier:
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.