Source:http://linkedlifedata.com/resource/pubmed/id/11602688
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
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| pubmed:dateCreated |
2001-10-16
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| pubmed:abstractText |
The concentrative Na+ nucleoside transporter type 2 (CNT2), cloned from a rat blood-brain barrier cDNA library, yields very high flux ratios for purine nucleosides after expression in frog oocytes. This high activity of the rat CNT2 produced from the blood-brain barrier-derived cDNA, designated clone A-11, enabled a kinetic analysis of 2',3'-dideoxyinosine transport via the rat CNT2. CNT2 transported both adenosine and 2',3'-dideoxyinosine. The 2',3'-dideoxyinosine transport parameters included a Km of 29.2 +/- 8.3 microM, a V(max) of 0.40 +/- 0.11 pmol/oocyte/min, and a constant of nonsaturable transport (KD) of 15.7 +/- 0.6 nl/oocyte/min. The 2',3'-dideoxyinosine Vmax was 27-fold lower than the adenosine Vmax and the 2',3'-dideoxyinosine KD was >15-fold greater than the KD of adenosine transport. Adenosine inhibited both the saturable component of 2',3'-dideoxyinosine transport with a K(I) of 14.8 +/- 1.6 microM, and inhibited the nonsaturable component of 2',3'-dideoxyinosine transport. Both the saturable and nonsaturable components of 2',3'-dideoxyinosine transport were sodium-dependent with a sodium K0.5 of 8.7 +/- 0.9 mM, and a Hill coefficient of 1.00 +/- 0.10. The transport of 2',3'-dideoxyinosine was strongly inhibited by thymidine, whereas thymidine was a weak inhibitor of adenosine transport via rat CNT2. Thymidine was transported by rat CNT2 with a Km = 130 +/- 44 microM and a Vmax = 1.7 +/- 0.5 pmol/oocyte/min. These studies provide evidence for asymmetric transport sites on rat CNT2, where 2',3'-dideoxyinosine and thymidine compete selectively at a low Vmax site on the transporter, whereas adenosine is transported at a high Vmax site.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine,
http://linkedlifedata.com/resource/pubmed/chemical/Didanosine,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger,
http://linkedlifedata.com/resource/pubmed/chemical/Thymidine,
http://linkedlifedata.com/resource/pubmed/chemical/cif nucleoside transporter
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| pubmed:status |
MEDLINE
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| pubmed:month |
Nov
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| pubmed:issn |
0022-3565
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
299
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
735-40
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| pubmed:dateRevised |
2007-11-14
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| pubmed:meshHeading |
pubmed-meshheading:11602688-Adenosine,
pubmed-meshheading:11602688-Animals,
pubmed-meshheading:11602688-Biological Transport,
pubmed-meshheading:11602688-Blood-Brain Barrier,
pubmed-meshheading:11602688-Clone Cells,
pubmed-meshheading:11602688-Didanosine,
pubmed-meshheading:11602688-Kinetics,
pubmed-meshheading:11602688-Membrane Transport Proteins,
pubmed-meshheading:11602688-Oocytes,
pubmed-meshheading:11602688-RNA, Messenger,
pubmed-meshheading:11602688-Rats,
pubmed-meshheading:11602688-Thymidine,
pubmed-meshheading:11602688-Xenopus
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| pubmed:year |
2001
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| pubmed:articleTitle |
Differential kinetics of transport of 2',3'-dideoxyinosine and adenosine via concentrative Na+ nucleoside transporter CNT2 cloned from rat blood-brain barrier.
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| pubmed:affiliation |
Department of Medicine, UCLA School of Medicine, Los Angeles, California, USA.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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