Structural flexibility of a helical peptide regulates vibrational energy transport properties.
Applying ultrafast vibrational spectroscopy, we find that vibrational energy transport along a helical peptide changes from inefficient but mostly ballistic below approximately 270 K into diffusive and significantly more efficient above. On the basis of molecular dynamics simulations, we attribute this change to the increasing flexibility of the helix above this temperature, similar to the glass transition in proteins. Structural flexibility enhances intramolecular vibrational energy redistribution, thereby refeeding energy into the few vibrational modes that delocalize over large parts of the structure and therefore transport energy efficiently. The paper outlines concepts how one might regulate vibrational energy transport properties in ultrafast photobiological processes, as well as in molecular electronic devices, by engineering the flexibility of their components.
Backus
Ellen H G
EH
Chemische Institute, Universitat Zurich, Winterthurerstr. 190, CH-8057 Zurich, Switzerland.
Nguyen
Phuong H
PH
Botan
Virgiliu
V
Moretto
Alessandro
A
Crisma
Marco
M
Toniolo
Claudio
C
Zerbe
Oliver
O
Stock
Gerhard
G
Hamm
Peter
P
D003198:Computer Simulation; D018360:Crystallography, X-Ray; D003903:Deuterium; D004735:Energy Transfer; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
D010455:Peptides; D003903:Deuterium