Linked Life Data

9192307

Source:http://linkedlifedata.com/resource/pubmed/id/9192307

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-8-1
pubmed:abstractText
1. Gating of the skeletal muscle chloride channel (ClC-1) is sensitive to extracellular pH. In this study, whole-cell recording of currents from wild-type (WT) ClC-1 and a mutant, R304E, expressed in the Sf-9 insect cell line was used to investigate further the nature of the pH-sensitive residues. 2. Extracellular Cd2+ produced a concentration-dependent block of WT ClC-1 with an IC50 of 1.0 +/- 0.1 mM and a Hill coefficient of 2.0 +/- 0.3. This block was sensitive to external pH, reducing at low pH, with an apparent pKa of 6.8 +/- 0.1 and a Hill coefficient for proton binding of 3.0 +/- 0.3. Anthracene-9-carboxylate (A-9-C) block of WT ClC-1 was also pH sensitive, increasing at low pH, with an apparent pKa of 6.4 +/- 0.1 and a Hill coefficient for proton binding of 1.0 +/- 0.2. 3. Compared with WT ClC-1, R304E had a lower affinity for Cd2+ (IC50, 3.0 +/- 0.3 mM) but it had a similar Hill coefficient for transition metal ion binding. The Hill coefficient for proton binding to the Cd2+ binding site was reduced to 1.4 +/- 0.3. In contrast, the A-9-C binding site in R304E showed the same pH sensitivity and affinity for the blocker as that seen in WT ClC-1. 4. ClC-1 has at least two binding sites for Cd2+, each of which has at least three residues which can be protonated. Binding of A-9-C is influenced by protonation of a single residue. Arg 304 is not sufficiently close to the A-9-C binding site to affect its characteristics, but it does. alter Cd2+ binding, indicating that transition metal ions and aromatic carboxylates interact with distinct sites. 5. The block of ClC-1 by transition metal ions and the apparent pKa of this block, together with the apparent pKa for A-9-C block and gating are all compatible with the involvement of His residues in the pore and gate of ClC-1.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-1283641, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-2436244, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-5316641, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-6040154, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-6040156, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-6310023, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-7646898, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-7694154, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-7845466, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-8112288, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-8130334, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-8189746, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-8241404, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-8639692, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-894246, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-8961185, http://linkedlifedata.com/resource/pubmed/commentcorrection/9192307-9064653
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-3751
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
501 ( Pt 2)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
355-62
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
pH-dependent interactions of Cd2+ and a carboxylate blocker with the rat C1C-1 chloride channel and its R304E mutant in the Sf-9 insect cell line.
pubmed:affiliation
Department of Physiology, University of Adelaide, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't