Transport of a fluorescent analogue of Glucose (2-NBDG) versus radiolabeled sugars by Rumen bacteria and Escherichia coli

dc.creatorTao, Junyi
dc.creatorDiaz, Rebecca K.
dc.creatorTeixeira, César R. V.
dc.creatorHackmann, Timothy J.
dc.date2018-04-20T14:46:38Z
dc.date2018-04-20T14:46:38Z
dc.date2016-04-20
dc.date.accessioned2023-09-27T20:52:59Z
dc.date.available2023-09-27T20:52:59Z
dc.identifier0006-2960
dc.identifierhttps://www.ncbi.nlm.nih.gov/pubmed/27096355
dc.identifierhttp://www.locus.ufv.br/handle/123456789/18953
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/8950074
dc.descriptionFluorescent tracers have been used to measure solute transport, but transport kinetics have not been evaluated by comparison of radiolabeled tracers. Using Streptococcus equinus JB1 and other bacteria, the objective of this study was to determine if a fluorescent analogue of glucose (2-NBDG) would be transported with the same kinetics and transporters as [14C]glucose. We uniquely modified a technique for measuring transport of radiolabeled tracers so that transport of a fluorescent tracer (2-NBDG) could also be measured. Deploying this technique for S. equinus JB1, we could detect 2-NDBG transport quantitatively and within 2 s. We found the Vmax of 2-NBDG transport was 2.9-fold lower than that for [14C]glucose, and the Km was 9.9-fold lower. Experiments with transport mutants suggested a mannose phosphotransferase system (PTS) was responsible for 2-NBDG transport in S. equinus JB1 as well as Escherichia coli. Upon examination of strains from 12 species of rumen bacteria, only the five that possessed a mannose PTS were shown to transport 2-NBDG. Those five uniformly transported [14C]mannose and [14C]deoxyglucose (other glucose analogues at the C-2 position) at high velocities. Species that did not transport 2-NBDG at detectable velocities did not possess a mannose PTS, though they collectively possessed several other glucose transporters. These results, along with retrospective genomic analyses of previous 2-NBDG studies, suggest that only a few bacterial transporters may display high activity toward 2-NBDG. Fluorescent tracers have the potential to measure solute transport qualitatively, but their bulky fluorescent groups may restrict (i) activity of many transporters and (ii) use for quantitative measurement.
dc.formatpdf
dc.formatapplication/pdf
dc.languageeng
dc.publisherBiochemistry
dc.relationv. 55, n. 18, p. 2578-2589, may 2016
dc.rightsAmerican Chemical Society
dc.subjectFluorescent analogue of glucose
dc.subjectRadiolabeled sugars
dc.subjectRumen bacteria and Escherichia coli
dc.subjectTransport
dc.titleTransport of a fluorescent analogue of Glucose (2-NBDG) versus radiolabeled sugars by Rumen bacteria and Escherichia coli
dc.typeArtigo


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