The Two-Dimensional Vibrational Echo of a Nitrile Probe of the Villin HP35 Protein

• DOI: 10.1021/jz101367d
• Publication Date: 2010-11-08T19:25:29Z
• Authors: Diana C. Urbanek; Dmitriy Yu. Vorobyev; Arnaldo L. Serrano; Feng Gai; Robin M. Hochstra...
• Keywords: 0103 physical sciences; 01 natural sciences

2D IR spectroscopy was used to probe the hydrophobic core structure of 35-residue Villin headpiece subdomain, HP35, by monitoring C≡N vibrational stretching band a cyano substituted phenylalanine (Phe). The presence two humps in frequency distribution folded equilibrium state is revealed. They represent states that exchange more slowly than ca. 10 ps. CN stretch mode peak frequencies (and their populations) are 2228.7 (44%) and 2234.5 cm(-1) (56%). modes have different frequency-frequency correlation times 7.4 ps 1.6 respectively. These results suggest population with higher group partly exposed whereas other experiences like environment.