| Autor: |
Lagos R; Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago., Wilkens M, Vergara C, Cecchi X, Monasterio O |
| Jazyk: |
angličtina |
| Zdroj: |
FEBS letters [FEBS Lett] 1993 Apr 26; Vol. 321 (2-3), pp. 145-8. |
| DOI: |
10.1016/0014-5793(93)80096-d |
| Abstrakt: |
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+ = 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. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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