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Article
Considerations for the Construction of the Solvation Correlation Function and Implications for the Interpretation of Dielectric Relaxation in Proteins
Journal of Physical Chemistry B
  • Sayantan Bose, Iowa State University
  • Ramkrishna Adhikary, Iowa State University
  • Prasun Mukherjee, Iowa State University
  • Xueyu Song, Iowa State University
  • Jacob W. Petrich, Iowa State University
Document Type
Article
Disciplines
Publication Version
Published Version
Publication Date
5-1-2009
DOI
10.1021/jp9004345
Abstract

The dielectric response of proteins is conveniently measured by monitoring the time-dependent Stokes shift of an associated chromophore. The interpretation of these experiments depends critically upon the construction of the solvation correlation function, C(t), which describes the time-dependence of the Stokes shift and hence the dielectric response of the medium to a change in charge distribution. We provide an analysis of various methods of constructing this function and review selected examples from the literature. The naturally occurring amino acid, tryptophan, has been frequently used as a probe of solvation dynamics in proteins. Its nonexponential fluorescence decay has stimulated the generation of an alternative method of constructing C(t). In order to evaluate this method, we have studied a system mimicking tryptophan. The system is comprised of two coumarins (C153 and C152) having different fluorescence lifetimes but similar solvation times. The coumarins are combined in different proportions in methanol to make binary probe mixtures. We use fluorescence upconversion spectroscopy to obtain wavelength-resolved kinetics of the individual coumarins in methanol as well as the binary mixtures of 75:25, 50:50, and 25:75 of C153:C152. The solvation correlation functions are constructed for these systems using different methods and are compared.

Comments

Reprinted (adapted) with permission from Journal of Physical Chemistry B 113 (2009): 11061, doi:10.1021/jp9004345. Copyright 2009 American Chemical Society.

Copyright Owner
American Chemical Society
Language
en
File Format
application/pdf
Citation Information
Sayantan Bose, Ramkrishna Adhikary, Prasun Mukherjee, Xueyu Song, et al.. "Considerations for the Construction of the Solvation Correlation Function and Implications for the Interpretation of Dielectric Relaxation in Proteins" Journal of Physical Chemistry B Vol. 113 Iss. 32 (2009) p. 11061 - 11068
Available at: http://works.bepress.com/xueyu-song/18/