Publication Date:
1988-09-23
Description:
Antibodies directed against a conserved intracellular segment of the sodium channel alpha subunit slow the inactivation of sodium channels in rat muscle cells. Of four site-directed antibodies tested, only antibodies against the short intracellular segment between homologous transmembrane domains III and IV slowed inactivation, and their effects were blocked by the corresponding peptide antigen. No effects on the voltage dependence of sodium channel activation or of steady-state inactivation were observed, but the rate of onset of the antibody effect and the extent of slowing of inactivation were voltage-dependent. Antibody binding was more rapid at negative potentials, at which sodium channels are not inactivated; antibody-induced slowing of inactivation was greater during depolarizations to more positive membrane potentials. The peptide segment recognized by this antibody appears to participate directly in rapid sodium channel inactivation during large depolarizations and to undergo a conformational change that reduces its accessibility to antibodies as the channel inactivates.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vassilev, P M -- Scheuer, T -- Catterall, W A -- NS 15751/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1988 Sep 23;241(4873):1658-61.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of Washington, School of Medicine, Seattle 98195.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2458625" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Antibodies
;
Cytoplasm/analysis
;
In Vitro Techniques
;
Ion Channels/*metabolism
;
Membrane Potentials
;
Molecular Sequence Data
;
Peptides/*metabolism
;
Rats
;
Sodium/*metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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