Simulations of two-dimensional infrared and stimulated resonance Raman spectra of photoactive yellow protein

We present simulations of one and two-dimensional infrared (2DIR) and stimulated resonance Raman (SRR) spectra of the dark state (pG) and early red-shifted intermediate (pR) of photoactive yellow protein (PYP). Shifts in the amide I and Glu46 COOH stretching bands distinguish between pG and pR in the IR absorption and 2DIR spectra. The one-dimensional SRR spectra are similar to the spontaneous RR spectra. The two-dimensional SRR spectra show large changes in cross peaks involving the C = O stretch of the two species and are more sensitive to the chromophore structure than 2DIR spectra.

Highlights► We simulated 2DIR and 2D-SRR spectra of the pG and pR intermediates of PYP. ► 2DIR spectra reveal shift in amide I band. ► 2D-SRR spectra show change in cross peaks associated with chromophore C = O stretch.