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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
12
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pubmed:dateCreated |
1997-4-29
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pubmed:abstractText |
Voltage-gated potassium (K(V)) channels play key roles in setting the resting potential and in the activation cascade of human peripheral T lymphocytes. Margatoxin (MgTX), a 39-amino acid peptide from Centruroides margaritatus, is a potent inhibitor of lymphocyte K(V) channels. The binding of monoiodotyrosinyl margatoxin ([125I]MgTX) to plasma membranes prepared from either Jurkat cells, a human leukemic T cell line, or CHO cells stably transfected with the Shaker-type voltage-gated K+ channel, K(V)1.3, has been used to investigate the properties of lymphocyte K(V) channels. These data were compared with [125I]MgTX binding to heterotetrameric K(V) channels in rat brain synaptic plasma membranes [Knaus, H. G., et al. (1995) Biochemistry 34, 13627-13634]. The affinity for [125I]MgTX is 100-200 fM in either Jurkat or CHO/K(V)1.3 membranes, and the receptor density is 20-120 fmol/mg in Jurkat membranes or 1000 fmol/mg in CHO/K(V)1.3 membranes. In contrast to rat brain, [125I]MgTX binding to Jurkat and CHO/K(V)1.3 membranes exhibits an absolute requirement for K+, with no potentiation of binding by Na+. K(V)1.3 was the only K(V)1 series channel present in either CHO/K(V)1.3 or Jurkat plasma membranes as determined by immunoprecipitation of [125I]MgTX binding or by Western blot analyses using sequence-specific antibodies prepared against members of the K(V)1 family. The relative potencies of a series of peptidyl K(V) channel inhibitors was essentially the same for inhibition of [125I]MgTX binding to Jurkat, CHO, or rat brain membranes and for blocking 86Rb+ efflux from the CHO/K(V)1.3 cells, except that alpha-dendrotoxin was more potent at blocking binding to rat brain membranes than in the other assays. The characteristics of [125I]MgTX binding, the antibody profiles, and the effects of the peptidyl K(V) inhibitors all indicate that the [125I]MgTX receptor in Jurkat lymphocytes is comprised of a homomultimer of K(V)1.3, unlike the heteromultimeric arrangement of the receptor in rat brain.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Iodine,
http://linkedlifedata.com/resource/pubmed/chemical/KCNA3 protein, human,
http://linkedlifedata.com/resource/pubmed/chemical/Kv1.3 Potassium Channel,
http://linkedlifedata.com/resource/pubmed/chemical/Neurotoxins,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels, Voltage-Gated,
http://linkedlifedata.com/resource/pubmed/chemical/Rubidium,
http://linkedlifedata.com/resource/pubmed/chemical/Scorpion Venoms,
http://linkedlifedata.com/resource/pubmed/chemical/margatoxin
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
36
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3737-44
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:9132027-Animals,
pubmed-meshheading:9132027-Blotting, Western,
pubmed-meshheading:9132027-CHO Cells,
pubmed-meshheading:9132027-Chromatography, High Pressure Liquid,
pubmed-meshheading:9132027-Cricetinae,
pubmed-meshheading:9132027-Humans,
pubmed-meshheading:9132027-Iodine,
pubmed-meshheading:9132027-Jurkat Cells,
pubmed-meshheading:9132027-Kinetics,
pubmed-meshheading:9132027-Kv1.3 Potassium Channel,
pubmed-meshheading:9132027-Neurotoxins,
pubmed-meshheading:9132027-Potassium Channels,
pubmed-meshheading:9132027-Potassium Channels, Voltage-Gated,
pubmed-meshheading:9132027-Rats,
pubmed-meshheading:9132027-Rubidium,
pubmed-meshheading:9132027-Scorpion Venoms
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pubmed:year |
1997
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pubmed:articleTitle |
Margatoxin binds to a homomultimer of K(V)1.3 channels in Jurkat cells. Comparison with K(V)1.3 expressed in CHO cells.
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pubmed:affiliation |
Department of Membrane Biochemistry and Biophysics, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
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