Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
29
|
| pubmed:dateCreated |
1992-11-18
|
| pubmed:abstractText |
The sulfhydryl-selective alkylating agent, N-ethylmaleimide (NEM), has been used as a tool to discern whether different binding domains exist on the neuronal serotonin (5-HT) transporter for 5-HT and 5-HT uptake inhibitors (Reith, M. E. A., Allen, D. L., Sershen, H., and Lajtha, A. (1984) J. Neurochem. 43, 249-255; Graham, D., Esnaud, H., Habert, E., and Langer, S. Z. (1989) Biochem. Pharmacol. 38, 3819-3826). However, relatively high concentrations of NEM and long incubation times have been required for inactivation of the transporter-binding site which raises the possibility that NEM is reacting with other nucleophilic groups (Smyth, D. G., Blumenfeld, O. O., and Konigsberg, W. (1964) Biochem. J. 91, 589-595). In the present work, the reactivity and essential nature of sulfhydryl groups associated with substrate/inhibitor binding to the neuronal 5-HT transporter was assessed. [3H]Paroxetine, a potent and selective 5-HT uptake inhibitor, was used to label the 5-HT transporter. The effects of a relatively wide range of sulfhydryl reagents on [3H]paroxetine binding in digitoninsolubilized preparations of rat brain neuronal membranes and the relative abilities of different classes of drugs to protect against NEM-induced inactivation of [3H]paroxetine binding were studied. It was observed that digitonin-solubilized preparations were more sensitive than membrane preparations to the inactivating effects of NEM. The pKa of the reactive group was estimated to be 6.17, in the range expected for a reactive sulfhydryl. Sulfhydryls essential to ligand binding reacted preferentially with hydrophobic compounds (p-hydroxymercuribenzoate = dithiobisnitrobenzoate > methyl methanethiosulfonate > N-phenylmaleimide > N-ethylmaleimide) and were unreactive toward hydrophilic reagents such as iodoacetate and iodoacetamide. 5-HT, 5-HT uptake inhibitors and cocaine protected the digitonin-solubilized transporter from NEM-induced inactivation while the amphetamine-related releasing agents p-chloroamphetamine and fenfluramine were ineffective. The observation that the binding of some, but not all, ligands requires reduced sulfhydryl groups, suggests that differential mechanisms and/or different binding domains do exist for agents which interact at the neuronal 5-HT transporter.
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| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Amphetamines,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Ethylmaleimide,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Glycoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Nerve Tissue Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Paroxetine,
http://linkedlifedata.com/resource/pubmed/chemical/Serotonin,
http://linkedlifedata.com/resource/pubmed/chemical/Serotonin Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Serotonin Plasma Membrane...,
http://linkedlifedata.com/resource/pubmed/chemical/Slc6a4 protein, rat,
http://linkedlifedata.com/resource/pubmed/chemical/Sulfhydryl Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Sulfhydryl Reagents
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0021-9258
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
15
|
| pubmed:volume |
267
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
20820-5
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| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:1400397-Amphetamines,
pubmed-meshheading:1400397-Animals,
pubmed-meshheading:1400397-Brain,
pubmed-meshheading:1400397-Carrier Proteins,
pubmed-meshheading:1400397-Cell Membrane,
pubmed-meshheading:1400397-Ethylmaleimide,
pubmed-meshheading:1400397-Kinetics,
pubmed-meshheading:1400397-Male,
pubmed-meshheading:1400397-Membrane Glycoproteins,
pubmed-meshheading:1400397-Membrane Transport Proteins,
pubmed-meshheading:1400397-Nerve Tissue Proteins,
pubmed-meshheading:1400397-Neurons,
pubmed-meshheading:1400397-Paroxetine,
pubmed-meshheading:1400397-Rats,
pubmed-meshheading:1400397-Rats, Sprague-Dawley,
pubmed-meshheading:1400397-Serotonin,
pubmed-meshheading:1400397-Serotonin Antagonists,
pubmed-meshheading:1400397-Serotonin Plasma Membrane Transport Proteins,
pubmed-meshheading:1400397-Sulfhydryl Compounds,
pubmed-meshheading:1400397-Sulfhydryl Reagents
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| pubmed:year |
1992
|
| pubmed:articleTitle |
Role of essential sulfhydryl groups in drug interactions at the neuronal 5-HT transporter. Differences between amphetamines and 5-HT uptake inhibitors.
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| pubmed:affiliation |
Lafayette Clinic, Detroit, Michigan 48207.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|