MICROCIN E492 FORMS ION CHANNELS IN PHOSPHOLIPID-BILAYER MEMBRANES

LAGOS, R; WILKENS, M; VERGARA, C; CECCHI, X; MONASTERIO, O

Abstract

Microcin E492, a polypeptide antibiotic, has been shown to have an M(r) of 6,000 by urea-SDS-polyacrylamide gel electrophoresis of the fluorescently labelled compound. It is known that the bactericidal action of microcin involves a loss of the transmembrane potential. In this study we show that microcin forms cation-selective channels in planar phospholipid bilayers. The channels have two main conductance states the current-voltage curves of which rectify. The reversal potentials measured under biionic conditions indicate a permeability sequence of NH4+ > K+ = Rb+ = Cs+ > Na+ = Li+ > Tris+. The results suggest that membrane potential dissipation induced by microcin is a consequence of the formation of pores in the bacterial membrane.

Más información

Título según WOS: ID WOS:A1993KY73900009 Not found in local WOS DB
Título de la Revista: FEBS LETTERS
Volumen: 321
Número: 2-3
Editorial: ELSEVIER SCIENCE BV
Fecha de publicación: 1993
Página de inicio: 145
Página final: 148
DOI:

10.1016/0014-5793(93)80096-D

Notas: ISI