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  3. Σχολή Επιστημών Υγείας
  4. Τμήμα Ιατρικής
  5. Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά) - ΙΑΤ
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Please use this identifier to cite or link to this item: https://olympias.lib.uoi.gr/jspui/handle/123456789/22639
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dc.contributor.authorFrillingos, S.en
dc.contributor.authorKaback, H. R.en
dc.date.accessioned2015-11-24T19:25:35Z-
dc.date.available2015-11-24T19:25:35Z-
dc.identifier.issn0006-2960-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/22639-
dc.rightsDefault Licence-
dc.subjectAmino Acid Sequenceen
dc.subjectBacterial Proteins/chemistry/genetics/*metabolismen
dc.subjectBiological Transport, Active/drug effects/geneticsen
dc.subjectCell Compartmentation/geneticsen
dc.subjectCysteine/geneticsen
dc.subjectDNA Mutational Analysis/methodsen
dc.subjectEnzyme Inhibitors/pharmacologyen
dc.subjectEscherichia coli/enzymology/genetics/*metabolismen
dc.subject*Escherichia coli Proteinsen
dc.subjectEthylmaleimide/pharmacologyen
dc.subjectLactose/metabolismen
dc.subjectMembrane Proteins/chemistry/genetics/*metabolismen
dc.subjectMembrane Transport Proteins/chemistry/genetics/*metabolismen
dc.subjectMolecular Sequence Dataen
dc.subject*Monosaccharide Transport Proteinsen
dc.subject*Protein Structure, Secondaryen
dc.subjectSulfhydryl Reagents/pharmacologyen
dc.subject*Symportersen
dc.titleCysteine-scanning mutagenesis of helix VI and the flanking hydrophilic domains on the lactose permease of Escherichia colien
heal.typejournalArticle-
heal.type.enJournal articleen
heal.type.elΆρθρο Περιοδικούel
heal.identifier.primary10.1021/bi953068d-
heal.identifier.secondaryhttp://www.ncbi.nlm.nih.gov/pubmed/8611521-
heal.identifier.secondaryhttp://pubs.acs.org/doi/pdfplus/10.1021/bi953068d-
heal.languageen-
heal.accesscampus-
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικήςel
heal.publicationDate1996-
heal.abstractUsing a functional lactose permease mutant devoid of Cys residues (C-less permease), each amino acid residue in putative transmembrane helix VI and the flanking hydrophilic loops (residues 164- 211) was replaced individually with Cys. Of the 48 mutants, 43 accumulate lactose at highly significant rates to > 80% of the steady state observed with C-less permease. Three mutants (Phe185--> Cys, Ala187--> Cys, and Phe208--> Cys) exhibit lower but significant levels of accumulation (30-60% of C-less). Cys replacement for Ala177 or Leu184 results in low transport activity (ca. 20%) in the C-less background but much higher activity (60-70%) in the wild type. Immunoblot analysis reveals that all of the mutants are inserted into the membrane at concentrations comparable to that of C-less perrmease. The transport activity of the great majority of the mutants is unaffected by treatment with N-ethylmaleimide (NEM). Relatively modest but significant inactivation (ca. 50%) is observed with mutants Phe170--> Cys, Gly173--> Cys, and Ala187--> Cys, and these positions cluster on the same face of the helix VI. Moreover, the two positions where single Cys replacements result in low activity (Ala177 and Lcu184) are on the same face of helix VI. The results demonstrate the following. (i) Permease function is not disrupted by replacement of most residues with Cys, but function is disrupted when some of the residues are further altered by addition of the NeM moiety. (ii) The latter residues lie on a stripe down one face of an alpha-helix, and within the same stripe are residues where Cys substitution itself leads ti inhibition of function.en
heal.journalNameBiochemistryen
heal.journalTypepeer-reviewed-
heal.fullTextAvailabilityTRUE-
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