Article thumbnail

Bacteriorhodopsin Analog Regenerated with 13-Desmethyl-13-Iodoretinal

By Kenji Hiraki, Toshiaki Hamanaka, Xiang-Guo Zheng, Teturo Shinada, Jong-Moon Kim, Kazuo Yoshihara and Yuji Kito


AbstractThe retinal analog 13-desmethyl-13-iodoretinal (13-iodoretinal) was newly synthesized and incorporated into apomembranes to reconstitute bacteriorhodopsin analog 13-I-bR. The absorption maximum was 598nm and 97% of the chromophore was an all-trans isomer in the dark- and light-adapted state. Upon flash illumination, 13-I-bR underwent a transient spectral change in which a shorter wavelength intermediate (λmax=426nm) similar to the M species of the native bR developed. Also, 13-I-bR showed light-induced proton pumping with rates and extents comparable to those seen in the native bR. The ultraviolet circular dichroism (CD) spectrum originating from the aromatic groups was different from that of the native bR, indicating that the substituted bulky iodine atom strongly interacts with neighboring amino acids. A projection difference Fourier map showed the labeled iodine was in the vicinity of helix C. 13-I-bR is an advantageous specimen for kinetic investigations of light-induced structural changes associated with the proton pumping cycle by x-ray diffraction

Publisher: The Biophysical Society. Published by Elsevier Inc.
Year: 2002
DOI identifier: 10.1016/S0006-3495(02)75345-9
OAI identifier:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • https://s3-eu-west-1.amazonaws... (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.