Proton transfers in a channelrhodopsin-1 studied by Fourier transform infrared (FTIR) difference spectroscopy and site-directed mutagenesis.

ABSTRACT: Channelrhodopsin-1 from the alga Chlamydomonas augustae (CaChR1) is a low-efficiency light-activated cation channel that exhibits properties useful for optogenetic applications such as a slow light inactivation and a red-shifted visible absorption maximum as compared with the more extensively studied channelrhodopsin-2 from Chlamydomonas reinhardtii (CrChR2). Previously, both resonance Raman and low-temperature FTIR difference spectroscopy revealed that unlike CrChR2, CaChR1 under our conditions exhibits an almost pure all-trans retinal composition in the unphotolyzed ground state and undergoes an all-trans to 13-cis isomerization during the primary phototransition typical of other microbial rhodopsins such as bacteriorhodopsin (BR). Here, we apply static and rapid-scan FTIR difference spe

SUBMITTER: Ogren JI 

PROVIDER: S-EPMC4432289 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature