Control of the Selectivity of the Aquaporin Water Channel Family by Global Orientational Tuning

@article{Tajkhorshid2002ControlOT,
  title={Control of the Selectivity of the Aquaporin Water Channel Family by Global Orientational Tuning},
  author={Emad Tajkhorshid and Peter San Francisco Nollert and Morten {\O}. Jensen and Larry J. W. Miercke and Joseph D. O'Connell and Robert M. Stroud and Klaus Schulten},
  journal={Science},
  year={2002},
  volume={296},
  pages={525 - 530}
}
Aquaporins are transmembrane channels found in cell membranes of all life forms. We examine their apparently paradoxical property, facilitation of efficient permeation of water while excluding protons, which is of critical importance to preserving the electrochemical potential across the cell membrane. We have determined the structure of the Escherichia coliaquaglyceroporin GlpF with bound water, in native (2.7 angstroms) and in W48F/F200T mutant (2.1 angstroms) forms, and carried out 12… Expand
Electrostatic tuning of permeation and selectivity in aquaporin water channels.
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The results indicate that the main barrier in aquaporin-1 is not, as had previously been speculated, caused by the interruption of the hydrogen-bonded water chain, but rather by an electrostatic field centered around the fingerprint Asn-Pro-Ala (NPA) motif. Expand
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It is found that, although the selectivity filter region is indeed central to substrate transport, other structural elements that do not directly interact with the substrates, such as the loop connecting helices M6 and M7, and the C loop between helices C4 and C5, play an essential role in facilitating selectivity. Expand
Molecular basis of proton blockage in aquaporins.
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This work examines the molecular basis for the blockage of proton translocation through the single-file water chain in the pore of a bacterial aquaporin, GlpF, and compute the reversible thermodynamic work for the two complementary steps of the Grotthuss "hop-and-turn" relay mechanism. Expand
Structure-function relationships in aquaporins.
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  • Materials Science, Medicine
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  • 2006
TLDR
The identification of members of the aquaporin family as the primary water channels of cell membranes has been followed up by an intense effort to determine how these channels work, and why these channels are selective for water and how they exclude proton trafficking. Expand
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The radii of the pores, the hydrogen-bond analysis, and the free energies show that it is easier for water molecules to permeate through the SF region of AQPZ with residue 174 in the Hse state than in theHsd state. Expand
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