Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-24997
Backus, E H G; Bloem, R; Pfister, R; Moretto, A; Crisma, M; Toniolo, C; Hamm, P (2009). Dynamical Transition in a Small Helical Peptide and Its Implication for Vibrational Energy Transport. Journal of Physical Chemistry. B, 113(40):13405-13409.
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The two-dimensional infrared spectrum of an octameric helical peptide in chloroform was measured as a function of temperature. Isotope labeling of the carbonyl group of one of the amino acids was used to obtain information for an isolated vibration. The antidiagonal width of the 2D-IR signal, which is a measure of the homogeneous dephasing time T2, is constant from 220 to 260 K (within experimental error), and increases steeply above. The homogeneous dephasing time of the carbonyl vibration is attributed to the flexibility of the system and/or its immediate surrounding. The system undergoes a dynamical transition at about 270 K, with similarities to the protein dynamical transition. Furthermore, the temperature dependence of the antidiagonal width strongly resembles that of the efficiency of vibrational energy transport along the helix, which has been studied in a recent paper (J. Phys. Chem. B 2008, 112, 15487). The connection between the two processes, structural flexibility and energy transport mechanism, is discussed.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Physical Chemistry|
|Date:||15 September 2009|
|Deposited On:||31 Dec 2009 10:55|
|Last Modified:||09 Jul 2012 06:02|
|Publisher:||American Chemical Society|
|Funders:||The Netherlands Organisation for Scientific Research (NWO) , Swiss National Science Foundation|
|WoS Citation Count:||9|
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