Colicin K acts by forming voltage-dependent channels in phospholipid bilayer membranes

Stanley J. Schein, Bruce L. Kagan, Alan Finkelstein

Research output: Contribution to journalArticle

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The bactericidal action of colicins K, E1, Ia, and other functionally related colicins involves disruption of active transport and leakage of ions from the cell. We show that a single colicin K molecule can form a voltage-dependent, relatively nonselective, ion-permeable channel of a few picosiemens conductance in a planar phospholipid bilayer membrane. In a membrane containing many of these channels, the ratio of the number of conducting to nonconducting channels changes e-fold per 3.7 mV. We suggest that the physiological effects of colicin K and functionally related colicins result from their ability to form ion-permeable channels in the bacterial plasma membrane.

Original languageEnglish (US)
Pages (from-to)159-163
Number of pages5
Issue number5684
Publication statusPublished - Dec 1 1978


ASJC Scopus subject areas

  • General

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