GENERIC 15590689

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Predicate	Object
rdf:type	pubmed:Citation
lifeskim:mentions	umls-concept:C0003968, umls-concept:C0017742, umls-concept:C0178487, umls-concept:C0205369, umls-concept:C0243071, umls-concept:C0596902, umls-concept:C0597484, umls-concept:C0851827, umls-concept:C1567844, umls-concept:C1701901, umls-concept:C1704259, umls-concept:C1705987
pubmed:issue	7
pubmed:dateCreated	2005-2-14
pubmed:abstractText	Vitamin C intracellular accumulation is mediated by Na(+)-dependent vitamin C transporters SVCT1 and -2 and dehydroascorbic acid transporters GLUT1 and -3. It is unclear which pathways dominate in vivo. As a new step to resolve this issue, we identified and tested 6-bromo-6-deoxy-L-ascorbic acid as a specific candidate for SVCTs. In high performance liquid chromatography and electron paramagnetic resonance analyses, the reduced compounds ascorbic acid and 6-bromo-6-deoxy-L-ascorbic acid were similar. The oxidized products 6-bromo-6-deoxy dehydroascorbic acid (BrDHA) and dehydroascorbic acid (DHA) had comparable stabilities, based on reduction recoveries. Upon expression of GLUT1 or GLUT3 in Xenopus oocytes, BrDHA was neither transported nor bound, in contrast to robust transport of DHA. The findings were not explained by differences in the oocyte reduction of DHA and BrDHA because lysed oocytes reduced both compounds equally. Further, there was no transport of the reduced compound, 6-bromo-6-deoxy-L-ascorbic acid, by GLUT1 or GLUT3. As a prerequisite for investigating 6-bromo-6-deoxy-L-ascorbic acid transported by SVCTs, SVCT2 transport activity in oocytes was enhanced 14-fold by construction and use of a vector that added a fixed poly(A) tail to the 3' end of cRNA. For SVCT1 and SVCT2 expressed in oocytes, similar K(m) and V(max) values were observed for ascorbic acid and 6-bromo-6-deoxy-L-ascorbic acid. In human fibroblasts, predicted to have SVCT-mediated ascorbate accumulation, K(m) and V(max) values were again comparable for ascorbic acid and 6-bromo-6-deoxy-L-ascorbic acid. Using activated human neutrophils, predicted to have ascorbate accumulation mediated predominantly by DHA and GLUT transporters, 6-bromo-6-deoxy-L-ascorbic acid accumulation was <1% of accumulation when compared with ascorbic acid. We conclude that 6-bromo-6-deoxy-L-ascorbic acid is the first transport substrate identified as completely specific for SVCTs, but not GLUTs, and provide a new strategy to determine the contribution of each pathway to ascorbate accumulation.
pubmed:language	eng
pubmed:journal	http://linkedlifedata.com/resource/pubmed/journal/2985121R
pubmed:citationSubset	IM
pubmed:chemical	http://linkedlifedata.com/resource/pubmed/chemical/6-deoxy-6-bromoascorbic acid, http://linkedlifedata.com/resource/pubmed/chemical/Ascorbic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Glucose, http://linkedlifedata.com/resource/pubmed/chemical/Monosaccharide Transport Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Organic Anion Transporters..., http://linkedlifedata.com/resource/pubmed/chemical/Poly A, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/SLC23A1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/SLC23A2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Sodium, http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Coupled Vitamin C..., http://linkedlifedata.com/resource/pubmed/chemical/Symporters
pubmed:status	MEDLINE
pubmed:month	Feb
pubmed:issn	0021-9258
pubmed:author	pubmed-author:CorpeChristopher PCP, pubmed-author:EckPeterP, pubmed-author:KirkKenneth LKL, pubmed-author:KwonOranO, pubmed-author:LeeJe-HyukJH, pubmed-author:LevineMarkM, pubmed-author:NarayananJayanJ
pubmed:issnType	Print
pubmed:day	18
pubmed:volume	280
pubmed:owner	NLM
pubmed:authorsComplete	Y
pubmed:pagination	5211-20
pubmed:dateRevised	2011-11-17
pubmed:meshHeading	pubmed-meshheading:15590689-Animals, pubmed-meshheading:15590689-Ascorbic Acid, pubmed-meshheading:15590689-Biological Transport, pubmed-meshheading:15590689-Chromatography, High Pressure Liquid, pubmed-meshheading:15590689-Electron Spin Resonance Spectroscopy, pubmed-meshheading:15590689-Fibroblasts, pubmed-meshheading:15590689-Glucose, pubmed-meshheading:15590689-Humans, pubmed-meshheading:15590689-Kinetics, pubmed-meshheading:15590689-Monosaccharide Transport Proteins, pubmed-meshheading:15590689-Neutrophils, pubmed-meshheading:15590689-Oocytes, pubmed-meshheading:15590689-Organic Anion Transporters, Sodium-Dependent, pubmed-meshheading:15590689-Oxidation-Reduction, pubmed-meshheading:15590689-Poly A, pubmed-meshheading:15590689-RNA, Messenger, pubmed-meshheading:15590689-Rats, pubmed-meshheading:15590689-Sodium, pubmed-meshheading:15590689-Sodium-Coupled Vitamin C Transporters, pubmed-meshheading:15590689-Symporters, pubmed-meshheading:15590689-Xenopus laevis
pubmed:year	2005
pubmed:articleTitle	6-Bromo-6-deoxy-L-ascorbic acid: an ascorbate analog specific for Na+-dependent vitamin C transporter but not glucose transporter pathways.
pubmed:affiliation	Molecular and Clinical Nutrition Section, Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1372, USA.
pubmed:publicationType	Journal Article