Resolving environmental microheterogeneity and dielectric relaxation in fluorescence kinetics of protein

Rolinski, O. J., McLaughlin, D., Birch, D. J.S. and Vyshemirsky, V. (2016) Resolving environmental microheterogeneity and dielectric relaxation in fluorescence kinetics of protein. Methods and Applications in Fluorescence, 4(2), 024001. (doi: 10.1088/2050-6120/4/2/024001)

Abstract

The fluorescence intensity decay of protein is easily measurable and reports on the intrinsic fluorophore-local environment interactions on the sub-nm spatial and sub-ns temporal scales, which are consistent with protein activity in numerous biomedical and industrial processes. This makes time-resolved fluorescence a perfect tool for understanding, monitoring and controlling these processes at the molecular level, but the complexity of the decay, which has been traditionally fitted to multi-exponential functions, has hampered the development of this technique over the last few decades. Using the example of tryptophan in HSA we present the alternative to the conventional approach to modelling intrinsic florescence intensity decay in protein where the key factors determining fluorescence decay, i.e. the excited-state depopulation and the dielectric relaxation (Toptygin and Brand 2000 Chem. Phys. Lett. 322 496–502), are represented by the individual relaxation functions. This allows quantification of both effects separately by determining their parameters from the global analysis of a series of fluorescence intensity decays measured at different detection wavelengths. Moreover, certain pairs of the recovered parameters of tryptophan were found to be correlated, indicating the influence of the dielectric relaxation on the transient rate of the electronic transitions. In this context the potential for the dual excited state depopulation /dielectric relaxation fluorescence lifetime sensing is discussed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Vyshemirsky, Dr Vladislav
• Authors: Rolinski, O. J., McLaughlin, D., Birch, D. J.S., and Vyshemirsky, V.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Statistics
• Journal Name: Methods and Applications in Fluorescence
• Publisher: IOP Publishing
• ISSN: 2050-6120
• ISSN (Online): 2050-6120
• Published Online: 30 March 2016
• Copyright Holders: Copyright © 2016 IOP Publishing Ltd
• First Published: First published in Methods and Applications in Fluorescence 4(2): 024001
• Publisher Policy: Reproduced in accordance with the publisher copyright policy