title: Equilibrium exchange processes of the aqueous tryptophan dipeptide.
abstract: The tryptophan dipeptide (NATMA) in D2O shows two conformers having distinctive acetyl end amide-I' transition frequencies. In 2D echo spectroscopy, cross peaks between these conformer transitions are used to show that they are undergoing exchange on the 1.5 ps time scale. Simulations suggest that the accessibility of the amide group to water is restricted in one of the conformations.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
authors.forename: Sayan
authors.initials: S
authors.lastname: Bagchi
authors.forename: Adam K
authors.initials: AK
authors.lastname: Charnley
authors.forename: Amos B
authors.initials: AB
authors.lastname: Smith Iii
authors.forename: Robin M
authors.initials: RM
authors.lastname: Hochstrasser
mesh_terms: D003198:Computer Simulation; D017666:Deuterium Oxide / Q000737:chemistry*; D004151:Dipeptides / Q000737:chemistry*; D008956:Models, Chemical; D013055:Spectrophotometry, Infrared; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D004151:Dipeptides; D014364:Tryptophan; D017666:Deuterium Oxide