In a recent J. Am. Chem. Soc. Communication, Professor Nien-Hui Ge and postdoctoral researcher Hiroaki Maekawa, in collaboration with the Toniolo group in Italy, reported the first observation of vibrational coupling between amide-I/II modes connected through a 310-helical intramolecular C=O•••H-N hydrogen bond. The combination of 2D IR spectroscopy and isotope substitutions with 13C=18O and 15N labels provides a new strategy for probing local peptide conformation, such as the formation of a single helix turn, a key step in protein folding processes.
Wednesday, February 11, 2009