Low-Frequency Vibrations and Their Role in Ultrafast Photoisomerization Reaction Dynamics of Photoactive Yellow Protein
Citations Over TimeTop 13% of 2004 papers
Abstract
Low-frequency vibrational modes of the native photoactive yellow protein (PYP) and its several mutant and analogue systems have been investigated in “time” (femtosecond fluorescence up-conversion) and “frequency” (resonance Raman spectroscopy) domains to elucidate their role in ultrafast photoisomerization reaction dynamics of PYP. The oscillatory frequencies derived from time-domain analysis are in fair agreement with those obtained independently using spontaneous resonance Raman spectroscopy. Tentative assignments of the oscillatory components to particular vibrations are proposed supported by normal-mode calculations based on density-functional theory and ab initio MO methods. It is concluded that the out-of-plane skeleton bending mode of the chromophore, γ16, is responsible for the observed oscillations in native and all mutant PYPs (f1 ≈ 135 cm-1), while in-plane ν‘42 and ν‘43 modes are probably responsible for oscillations observed in the PYP analogue with locked chromophore. The low-frequency mode (f2 ≈ 50 cm-1) present in time-domain experiments of all systems examined could not be fully characterized. A dynamic model called “trigger mode mediated guidance” has been proposed to explain in simple terms the ultrafast primary process initiating PYP's photocycle. This work provides a framework for future investigations on PYP's low-frequency vibrational modes in connection with its primary structural photodynamics.
Related Papers
- → Relating normal vibrational modes to local vibrational modes with the help of an adiabatic connection scheme(2012)133 cited
- → On the relationship of normal modes to local modes in molecular vibrations(1985)420 cited
- → Direct targeting of adsorbate vibrations with mode-tracking(2006)20 cited
- → A Pictorial Visualization of Normal Mode Vibrations of the Fullerene (C60) Molecule in Terms of Vibrations of a Hollow Sphere(2010)4 cited
- → ViPA: A computer program for vector projection analysis of normal vibrational modes of molecules(1998)29 cited