Tunable laser resonance Raman spectroscopy of the visual process. I: The spectrum of rhodopsin

Tunable laser resonance Raman spectra have been obained of a solution of bovine rhodopsin. The spectra were obtained without causing the cis‐trans isomerization of the retinylidene chromophore which is the primary photochemical act in vision. The spectra appear to be sensitive to the structure, the environment and the interactions of the retinylidene chromophore in its opsin matrix. The ease with which the spectra were obtained, the experimental flexibility of Raman spectroscopy and the apparent sensitivity of the spectra suggests a wide range of possible applications for resonance Raman spectroscopy in the elucidation of the principal molecular steps in vision.