Document Detail


Characterisation of channels induced in planar bilayer membranes by detergent solubilised Escherichia coli porins.
MedLine Citation:
PMID:  2410024     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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.
Authors:
J H Lakey; J P Watts; E J Lea
Related Documents :
20224214 - Aquaporin 1 water channel is overexpressed in the plasma membranes of pancreatic ducts ...
2449254 - Electrostatic radius of the gramicidin channel determined from voltage dependence of h+...
15473074 - Dynamic ion channel activation scheduling in patch clamp on a chip.
8386354 - Multiple levels of native cardiac na+ channels at elevated temperature measured with hi...
19662214 - Electron pathways through erythrocyte plasma membrane in human physiology and pathology...
8452864 - Interaction of the yeast phosphatidylserine transfer protein with artificial and biolog...
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    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Bacterial Outer Membrane Proteins / pharmacology
Detergents
Escherichia coli / analysis*,  drug effects
Ion Channels / analysis*,  drug effects
Lipid Bilayers / analysis*
Mathematics
Membrane Potentials
Octoxynol
Permeability
Polyethylene Glycols
Porins
Sodium Dodecyl Sulfate
Solubility
Chemical
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


Previous Document:  Spectroscopic assessment of secondary and tertiary structure in myelin basic protein.
Next Document:  The role of microtubules and microfilaments in the hydrosmotic response to antidiuretic hormone.