Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Sulfate transport by tobacco cells (Nicotiana tabacum L. var. Xanthi) cultured in liquid medium was investigated.Transport was linear with time, had a sharp pH optimum between 6.5 and 7.5, and obeyed Michaelis-Menten kinetics. The Km varied within the range 2 x 10(-5)m and 4 x 10(-5)m and the maximum velocity was in the range 100 to 400 nanomoles per gram fresh weight.hour.Transport was inhibited more than 90% by 10(-4)m sulfite, thiosulfate, metabisulfite, sulfide, selenate, and chromate, but was inhibited less than 40% by 10(-3)m chloride, nitrate, or phosphate. Selenate was a competitive and sulfide a noncompetitive inhibitor of sulfate transport.The oxidative respiration inhibitors, azide and cyanide, uncoupling reagents, carbonylcyanide m-chlorophenylhydrazone (CCCP) and dinitrophenol, and the ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD) were all potent inhibitors of transport. Inhibition by CCCP was not prevented by preincubation of cells with dithiothreitol. Removal of CCCP from the transporting medium resulted in a partial resumption of transport, in contrast removal of DCCD had no effect.Sulfate transport was inhibited more than 90% by 10(-4)m mercaptoethanol, dithiothreitol, or d-cysteine and was abolished by either 10(-5)m N-ethylmaleimide or 10(-4)m iodoacetamide. Removal of mercaptoethanol from the transporting medium resulted in a return to maximal rates of transport whereas when either N-ethylmaleimide or iodoacetamide were removed transport remained inhibited.N-ethylmaleimide (10(-5)m) and iodoacetamide (10(-4)m), which inhibited transport completely, induced the efflux of between 70 and 90% of the transported sulfate in 5 hours. Metabolite efflux was induced by the following compounds, which are listed according to their effectiveness, DCCD, CCCP, mercaptoethanol, and selenate. Increasing the concentration of an inhibitor, in excess of that required to inhibit transport 100%, increased the rate of nonspecific metabolite efflux from the cells.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-124553, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-13954345, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-16654867, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-16656483, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-16657199, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-16657321, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-16658725, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-167875, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-4276129, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-4279625, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-4344983, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-4597558, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-4941946, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-5221239, http://linkedlifedata.com/resource/pubmed/commentcorrection/16659678-5774773
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Sep
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
358-62
pubmed:dateRevised
2010-9-14
pubmed:year
1976
pubmed:articleTitle
Characterization of sulfate transport in cultured tobacco cells.
pubmed:affiliation
Department of Botany, Ohio University, Athens, Ohio 45701.
pubmed:publicationType
Journal Article