Linked Life Data

1383206

Source:http://linkedlifedata.com/resource/pubmed/id/1383206

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
1992-11-18
pubmed:abstractText
We characterized the electrophysiological properties of a chloride channel protein isolated from bovine trachea after incorporation into planar lipid bilayers, and studied the effects of thiol-modulating agents on channel regulation both in bilayers and vesicular iodide uptake studies. Our experiments showed that this protein formed perfectly anion-selective channels in the bilayer, with an anion permeability sequence of I- (2.1) > NO3- (1.7) > Br- (1.2) > Cl- (1.0). The conductance of this channel was 25-30 picosiemens in 150 mM Cl-, and saturated with increasing chloride concentration. This channel could be completely inhibited by 4,4'-bis(isothiocyano)-2,2'-stilbenedisulfonate. Immunoblot analysis, using polyclonal antibodies (anti-p38), revealed one major band at 140 kDa. Upon reduction with dithiothreitol, 64- and 38-kDa polypeptides were observed. Functional experiments showed that reduction was accompanied by loss of 125I- uptake and single-channel activity. In the presence of dithiothreitol, only the low molecular mass protein forms (64 and 38 kDa) were detected by anti-p38 antibodies on Western blots. Cross-linking of S-S bonds with Cu(2+)-o-phenanthroline led to activation of chloride channels in vesicles and bilayers. Over-aggregation of chloride channels by this S-S cross-linking reagent caused inhibition of 125I- uptake by 80-100% and the abolishment of single-channel activity. We propose that the native chloride channel from bovine trachea can exist in vivo in different structural and functional forms depending upon its thiol-disulfide oxidation reduction status. The oxidized form has a molecular mass of 140 kDa and represents a fully active chloride channel. Inactivation of this channel might occur by over-aggregation of protein subunits, or by dissociation of the 140-kDa subunit by disulfide bond reduction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20630-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:1383206-4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid, pubmed-meshheading:1383206-4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid, pubmed-meshheading:1383206-Animals, pubmed-meshheading:1383206-Blotting, Western, pubmed-meshheading:1383206-Cattle, pubmed-meshheading:1383206-Chloride Channels, pubmed-meshheading:1383206-Dithiothreitol, pubmed-meshheading:1383206-Electric Conductivity, pubmed-meshheading:1383206-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:1383206-Ion Channels, pubmed-meshheading:1383206-Kinetics, pubmed-meshheading:1383206-Lipid Bilayers, pubmed-meshheading:1383206-Macromolecular Substances, pubmed-meshheading:1383206-Membrane Potentials, pubmed-meshheading:1383206-Membrane Proteins, pubmed-meshheading:1383206-Muscle, Smooth, pubmed-meshheading:1383206-Proteolipids, pubmed-meshheading:1383206-Time Factors, pubmed-meshheading:1383206-Trachea
pubmed:year
1992
pubmed:articleTitle
Functional reconstitution of a chloride channel protein from bovine trachea.
pubmed:affiliation
Department of Physiology and Biophysics, University of Alabama, Birmingham 35294.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't