Document Detail

Characterisation of channels induced in planar bilayer membranes by detergent solubilised Escherichia coli porins.
MedLine Citation:
PMID:  2410024     Owner:  NLM     Status:  MEDLINE    
Purified OmpF, OmpC, NmpC, PhoE and Lc (Protein 2) porins from the Escherichia coli outer membrane were incorporated into planar phospholipid bilayer membranes and the permeability properties of the pores studied. Triton X-100 solubilised porin samples showed large and reproducible increases in membrane conductivity composed of discreet single-channel events. The magnitude of the cation selectivity found for the porins was in the order OmpC greater than OmpF greater than NmpC = Lc; PhoE was anion selective. For the cation selective porins the cation/anion permeability ratios in a variety of solutes ranged from 6 to 35. Further information on the internal structure of the porins was obtained by examination of the single-channel conductance and this was used to interpret macroscopic observations and to estimate single-channel diameters. The same porins solubilised in SDS exhibited slight conductance increase with no observable single-channel activity. Use of on-line microcomputer techniques confirmed the ohmic current vs. voltage behaviour for all the single porin channels examined.
J H Lakey; J P Watts; E J Lea
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  817     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  1985 Jul 
Date Detail:
Created Date:  1985-09-05     Completed Date:  1985-09-05     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  208-16     Citation Subset:  IM    
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MeSH Terms
Bacterial Outer Membrane Proteins / pharmacology
Escherichia coli / analysis*,  drug effects
Ion Channels / analysis*,  drug effects
Lipid Bilayers / analysis*
Membrane Potentials
Polyethylene Glycols
Sodium Dodecyl Sulfate
Reg. No./Substance:
0/Bacterial Outer Membrane Proteins; 0/Detergents; 0/Ion Channels; 0/Lipid Bilayers; 0/Polyethylene Glycols; 0/Porins; 151-21-3/Sodium Dodecyl Sulfate; 9002-93-1/Octoxynol

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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