channelrhodopsins

In channelrhodopsin, photon absorption leads to retinal isomerization within femtoseconds, conductive states are reached on the microsecond timescale, and return to the fully dark-adapted state may take more than minutes.

Despite wide use of channelrhodopsins, their photocycles and the mechanisms of ion channel gating and conductance remain insufficiently understood.

A range of different spectroscopical approaches is necessary to cover the full set of channelrhodopsin time regimes from ultrafast photochemistry to slow dark-state recovery.

Infrared spectroscopy is a preferred method for studying channelrhodopsins because it allows observation of proteins and their function at a molecular level and in near-native environment.

Channelrhodopsin properties such as channel selectivity, timing parameters, and color can be influenced by exchange of selected amino acids.