In channelrhodopsin-2 Glu-90 is crucial for ion selectivity and is deprotonated during the photocycle.

ABSTRACT: The light-activated microbial ion channel channelrhodopsin-2 (ChR2) is a powerful tool to study cellular processes with high spatiotemporal resolution in the emerging field of optogenetics. To customize the channel properties for optogenetic experiments, a detailed understanding of its molecular reaction mechanism is essential. Here, Glu-90, a key residue involved in the gating and selectivity mechanism of the ion channel is characterized in detail. The deprotonation of Glu-90 during the photocycle is elucidated by time-resolved FTIR spectroscopy, which seems to be part of the opening mechanism of the conductive pore. Furthermore, Glu-90 is crucial to ion selectivity as also revealed by mutation of this residue combined with voltage clamp experiments. By dynamic homology modeling, we furth

SUBMITTER: Eisenhauer K 

PROVIDER: S-EPMC3307317 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature