Detecting protein-protein interactions by isotope-edited infrared spectroscopy: a numerical approach.
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.
Zehender
Fabian
F
Institut für Physikalische Chemie, Universität Freiburg, Albertstrasse 23a, D-79104 Freiburg im Breisgau, Germany.
Labahn
Andreas
A
Koslowski
Thorsten
T
D000465:Algorithms; D002247:Carbon Isotopes / Q000737:chemistry*; D019281:Dimerization; D006096:Gramicidin / Q000737:chemistry; D007554:Isotopes; D008958:Models, Molecular; D010100:Oxygen / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared
D002247:Carbon Isotopes; D007554:Isotopes; D011506:Proteins; D006096:Gramicidin; D010100:Oxygen