Ultrafast spectra and kinetics of human green-cone visual pigment at room temperature

Rhodopsin is the pigment that enables night vision, whereas cone opsins are the pigments responsible for color vision in bright-light conditions. Despite their importance for vision, cone opsins are poorly characterized at the molecular level compared to rhodopsin. Spectra and kinetics of the intermediate states of human green-cone visual pigment (mid-wavelength sensitive, or MWS opsin) were measured and compared with the intermediates and kinetics of bovine rhodopsin. All the major intermediates of the MWS opsin were recorded in the picosecond to millisecond time range. Several intermediates in MWS opsin appear to have characteristics similar to the intermediates of bovine rhodopsin; however, there are some marked differences. One of the most striking differences is in their kinetics, where the kinetics of the MWS opsin intermediates are slower compared to those of the bovine rhodopsin intermediates.

Automated summary

Rhodopsin enables night vision, while cone opsins are responsible for color vision in bright-light conditions. The molecular characterization of cone opsins, compared to rhodopsin, is less understood. The spectra and kinetics of the intermediates of human green-cone visual pigment (MWS opsin) were measured and compared to bovine rhodopsin. The major intermediates of MWS opsin were observed within the picosecond to millisecond time range. Although some intermediates of MWS opsin show similarities to bovine rhodopsin, there are notable differences, especially in their kinetics.