The chromophore structure of the long-lived intermediate of the C128T channelrhodopsin-2 variant

FEBS Lett. 2011 Dec 15;585(24):3998-4001. doi: 10.1016/j.febslet.2011.11.007. Epub 2011 Nov 13.

Abstract

The photocycle of the light-activated channel, channelrhodopsin-2 C128T, has been studied by resonance Raman (RR) spectroscopy focussing on the intermediates P380 and P353 that constitute a side pathway in the recovery of the parent state. The P353 species displays a UV-vis absorption spectrum with a fine-structure reminiscent of the reduced-retro form of bacteriorhodopsin, whereas the respective RR spectra differ substantially. Instead, the RR spectra of the P380/P353 intermediate couple are closely related to that of a free retinal in the all-trans configuration. These findings imply that the parent state recovery via P380/P353 involves the transient hydrolysis and re-formation of the retinal-protein linkage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Channelrhodopsins
  • Color
  • Humans
  • Hydrogen-Ion Concentration
  • Mutant Proteins / chemistry*
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism*
  • Mutation*
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Spectrophotometry, Ultraviolet
  • Spectrum Analysis, Raman

Substances

  • Channelrhodopsins
  • Mutant Proteins
  • Nerve Tissue Proteins