Crystallographic characterization by X-ray diffraction of the M-intermediate from the photo-cycle of bacteriorhodopsin at room temperature

Masayoshi Nakasako, Mikio Kataoka, Yoshiyuki Amemiya, Fumio Tokunaga

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The structure of the M-intermediate appearing in the photo-cycle of bacteriorhodopsin was studied with X-ray diffraction techniques at room temperature. The lifetime of the M-intermediate was prolonged by treatment with an arginine solution at alkaline pH (Nakasako et al.,FEBS Lett. 254, 211-214). The diffraction profile of membranes which had accumulated the M-intermediate had small but significant differences in the intensities of Bragg reflections and the lattice constant in comparison with that of membranes having trans-bacteriorhodopsin. Diffraction intensities were carefully evaluated and the structural changes during the formation of the intermediate were evaluated with difference Fourier analysis. We could find structural changes around helices G and B.

Original languageEnglish
Pages (from-to)73-75
Number of pages3
JournalFEBS Letters
Issue number1-2
Publication statusPublished - 1991 Nov 4
Externally publishedYes



  • Bacteriorhodopsin
  • M-intermediate
  • Purple membrane
  • X-ray diffraction

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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