Theoretical spectroscopy

The structure and dynamics of proteins are manifest in infrared and UV/Vis spectra that may be easily recorded (ok, comparatively). The interaction of the absorbing units are, however, not understood to a degree to make use of all of the spectroscopically accessible information. For a characteristic absorption band in the infrared, the amide I band (C=O stretch, see figure) we have suggested a procedure that makes us of specific isotope substitutions to generate a spectral coupling pattern, which in turn permits to assign pairs of peptide groups in a close spatial vicinity. In cooperation with an experimental group, we hope to obtain information about proteins that cannot be easily accessed using x-ray or NMR techniques, such as membrane proteins.

We have recently started to reparametrize a semiempirical method incorporating configuration interaction for ubiquitous chromophores and aromatic amino acid side chains and to adapt the method to large systems. We aim at the UV/Vis spectra and the charge carrier dynamics of protein complexes and models of organic solar cells.