WeightNameValue
1000 Titel
  • Highly selective water channel activity measured by voltage clamp: Analysis of planar lipid bilayers reconstituted with purified AqpZ
1000 Autor/in
  1. Pohl, Peter |
  2. Saparov, Sapar M. |
  3. Borgnia, Mario J. |
  4. Agre, Peter |
1000 Erscheinungsjahr 2001
1000 LeibnizOpen
1000 Publikationstyp
  1. Artikel |
1000 Online veröffentlicht
  • 2001-08-07
1000 Erschienen in
1000 Quellenangabe
  • 98(17): 9624-9629
1000 FRL-Sammlung
1000 Verlagsversion
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC55502/ |
  • http://dx.doi.org/10.1073/pnas.161299398 |
1000 Publikationsstatus
1000 Begutachtungsstatus
1000 Sprache der Publikation
1000 Abstract/Summary
  • Aquaporins are membrane channels selectively permeated by water or water plus glycerol. Conflicting reports have described ion conductance associated with some water channels, raising the question of whether ion conductance is a general property of the aquaporin family. To clarify this question, a defined system was developed to simultaneously measure water permeability and ion conductance. The Escherichia coli water channel aquaporin-Z (AqpZ) was studied, because it is a highly stable tetramer. Planar lipid bilayers were formed from unilamellar vesicles containing purified AqpZ. The hydraulic conductivity of bilayers made from the total extract of E. coli lipids increased 3-fold if reconstituted with AqpZ, but electric conductance was unchanged. No channel activity was detected under voltage-clamp conditions, indicating that less than one in 109 transport events is electrogenic. Microelectrode measurements were simultaneously undertaken adjacent to the membrane. Changes in sodium concentration profiles accompanying transmembrane water flow permitted calculation of the activation energies: 14 kcal/mol for protein-free lipid bilayers and 4 kcal/mol for lipid bilayers containing AqpZ. Neither the water permeability nor the electric conductivity exhibited voltage dependence. This sensitive system demonstrated that AqpZ is permeated by water but not charged ions and should permit direct analyses of putative electrogenic properties of other aquaporins.
1000 Fachgruppe
  1. Biologie |
1000 Fächerklassifikation (DDC)
1000 Liste der Beteiligten
  1. http://orcid.org/0000-0002-1792-2314|https://frl.publisso.de/adhoc/creator/U2FwYXJvdiwgU2FwYXIgTS4=|https://frl.publisso.de/adhoc/creator/Qm9yZ25pYSwgTWFyaW8gSi4=|https://frl.publisso.de/adhoc/creator/QWdyZSwgUGV0ZXI=
1000 Förderer
  1. Deutsche Forschungsgemeinschaft (DFG) |
  2. National Institutes of Health (NIH) |
1000 Fördernummer
  1. Po 533/2–3; Po 533/7–1
  2. HL33991; HL48268; EY11239
1000 Förderprogramm
  1. -
  2. -
1000 Förderung
  1. 1000 joinedFunding-child
    1000 Förderer Deutsche Forschungsgemeinschaft (DFG) |
    1000 Förderprogramm -
    1000 Fördernummer Po 533/2–3; Po 533/7–1
  2. 1000 joinedFunding-child
    1000 Förderer National Institutes of Health (NIH) |
    1000 Förderprogramm -
    1000 Fördernummer HL33991; HL48268; EY11239
1000 Objektart article
1000 Beschrieben durch
1000 @id frl:6404877.rdf
1000 Erstellt am 2017-10-09T12:10:16.201+0200
1000 Erstellt von 122
1000 beschreibt frl:6404877
1000 Bearbeitet von 218
1000 Zuletzt bearbeitet Wed Aug 01 11:52:59 CEST 2018
1000 Objekt bearb. Wed Aug 01 11:52:58 CEST 2018
1000 Vgl. frl:6404877
1000 Oai Id
  1. oai:frl.publisso.de:frl:6404877 |
1000 Sichtbarkeit Metadaten public
1000 Sichtbarkeit Daten public
1000 Gegenstand von

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