Abstract:
:A form of two-dimensional (2D) vibrational spectroscopy, which uses two ultrafast IR laser pulses, is used to examine the structure of a cyclic penta-peptide in solution. Spectrally resolved cross peaks occur in the off-diagonal region of the 2D IR spectrum of the amide I region, analogous to those in 2D NMR spectroscopy. These cross peaks measure the coupling between the different amide groups in the structure. Their intensities and polarizations relate directly to the three-dimensional structure of the peptide. With the help of a model coupling Hamiltonian, supplemented by density functional calculations, the spectra of this penta-peptide can be regenerated from the known solution phase structure. This 2D-IR measurement, with an intrinsic time resolution of less than 1 ps, could be used in all time regimes of interest in biology.
journal_name
Proc Natl Acad Sci U S Aauthors
Hamm P,Lim M,DeGrado WF,Hochstrasser RMdoi
10.1073/pnas.96.5.2036keywords:
subject
Has Abstractpub_date
1999-03-02 00:00:00pages
2036-41issue
5eissn
0027-8424issn
1091-6490journal_volume
96pub_type
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