Utilizing Lifetimes to Suppress Random Coil Features in 2D IR Spectra of Peptides
Year: 2011
Type: article
Abstract: We report that the waiting time delay in 2D IR pulse sequences can be used to suppress signals from structurally disordered regions of amyloid fibrils. At a waiting time delay of 1.0 ps, the random coil vibrational modes of amylin fibrils are no longer detectable, leaving only the sharp excitonic vibrational features of the fibril β-sheets. Isotope labeling with (13)C(18)O reveals that structurally disordered residues decay faster than residues protected from solvent. Since structural disorder is usually accompanied by hydration, we conclude that the shorter lifetimes of random-coil residues is due to solvent exposure. These results indicate that 2D IR pulse sequences can utilize the waiting time to better resolve solvent-protected regions of peptides and that local mode lifetimes should be included in simulations of 2D IR spectra.
DOI: 10.1021/jz201024m
Institution: University of Wisconsin–Madison
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2075716695