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High resolution AFM topographs of the Escherichia coli water channel aquaporin Z.

Publication ,  Journal Article
Scheuring, S; Ringler, P; Borgnia, M; Stahlberg, H; Müller, DJ; Agre, P; Engel, A
Published in: EMBO J
September 15, 1999

Aquaporins form a large family of membrane channels involved in osmoregulation. Electron crystallography has shown monomers to consist of six membrane spanning alpha-helices confirming sequence based predictions. Surface exposed loops are the least conserved regions, allowing differentiation of aquaporins. Atomic force microscopy was used to image the surface of aquaporin Z, the water channel of Escherichia coli. Recombinant protein with an N-terminal fragment including 10 histidines was isolated as a tetramer by Ni-affinity chromatography, and reconstituted into two-dimensional crystals with p42(1)2 symmetry. Small crystalline areas with p4 symmetry were found as well. Imaging both crystal types before and after cleavage of the N-termini allowed the cytoplasmic surface to be identified; a drastic change of the cytoplasmic surface accompanied proteolytic cleavage, while the extracellular surface morphology did not change. Flexibility mapping and volume calculations identified the longest loop at the extracellular surface. This loop exhibited a reversible force-induced conformational change.

Duke Scholars

Published In

EMBO J

DOI

ISSN

0261-4189

Publication Date

September 15, 1999

Volume

18

Issue

18

Start / End Page

4981 / 4987

Location

England

Related Subject Headings

  • Surface Properties
  • Recombinant Proteins
  • Protein Structure, Secondary
  • Protein Conformation
  • Molecular Sequence Data
  • Microscopy, Atomic Force
  • Membrane Proteins
  • Escherichia coli Proteins
  • Escherichia coli
  • Developmental Biology
 

Citation

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Scheuring, S., Ringler, P., Borgnia, M., Stahlberg, H., Müller, D. J., Agre, P., & Engel, A. (1999). High resolution AFM topographs of the Escherichia coli water channel aquaporin Z. EMBO J, 18(18), 4981–4987. https://doi.org/10.1093/emboj/18.18.4981
Scheuring, S., P. Ringler, M. Borgnia, H. Stahlberg, D. J. Müller, P. Agre, and A. Engel. “High resolution AFM topographs of the Escherichia coli water channel aquaporin Z.EMBO J 18, no. 18 (September 15, 1999): 4981–87. https://doi.org/10.1093/emboj/18.18.4981.
Scheuring S, Ringler P, Borgnia M, Stahlberg H, Müller DJ, Agre P, et al. High resolution AFM topographs of the Escherichia coli water channel aquaporin Z. EMBO J. 1999 Sep 15;18(18):4981–7.
Scheuring, S., et al. “High resolution AFM topographs of the Escherichia coli water channel aquaporin Z.EMBO J, vol. 18, no. 18, Sept. 1999, pp. 4981–87. Pubmed, doi:10.1093/emboj/18.18.4981.
Scheuring S, Ringler P, Borgnia M, Stahlberg H, Müller DJ, Agre P, Engel A. High resolution AFM topographs of the Escherichia coli water channel aquaporin Z. EMBO J. 1999 Sep 15;18(18):4981–4987.

Published In

EMBO J

DOI

ISSN

0261-4189

Publication Date

September 15, 1999

Volume

18

Issue

18

Start / End Page

4981 / 4987

Location

England

Related Subject Headings

  • Surface Properties
  • Recombinant Proteins
  • Protein Structure, Secondary
  • Protein Conformation
  • Molecular Sequence Data
  • Microscopy, Atomic Force
  • Membrane Proteins
  • Escherichia coli Proteins
  • Escherichia coli
  • Developmental Biology