Detecting Protein−Protein Interactions by Isotope-Edited Infrared Spectroscopy: A Numerical Approach
F. Zehender, Andreas Labahn, Thorsten Koslowski · The Journal of Physical Chemistry B · 2005
We present a theoretical and numerical analysis of the vibrational coupling between isotope-edited amino acids in protein dimers. Depending on the presence and magnitude of coupling between 13Calpha=O peptide bond oscillators, characteristic level splittings of vibrational eigenstates are predicted. For the example of the Gramicidin A ion channel polypeptide, we observe typical IR fingerprints for the head-to-head and the antiparallel double-helical conformation of the dimer. We suggest that these findings can be used to clearly identify the structure of polypeptide aggregates using a particularly simple isotope substitution pattern.