Fig. 3.

Absorption spectrum (Top), transient difference spectra at selected delay times (Middle), and stationary cis-trans difference spectrum measured in the FTIR spectrometer (Bottom) of the linear precursor peptide linAMPB. The responses with both parallel (filled circles) and perpendicular (open circles) polarization of pump and probe pulses are shown (both have been measured simultaneously and have not been scaled with respect to each other; see Materials and Methods). The FTIR difference and absorption spectra have been scaled to facilitate direct comparison with the time-resolved spectra. The scale of the time-resolved spectra is the same as in Fig. 2.