Biology Reference
In-Depth Information
Fluorescence Lifetime of Fluorescent Proteins
Gregor Jung, Andreas Brockhinke, Thomas Gensch, Benjamin H
otzer,
Stefanie Schwedler, and Seena Koyadan Veettil
Abstract Fluorescence is a photophysical phenomenon, which obeys basic physical
laws. The fluorescence of the autofluorescent proteins arises on the molecular level
from chromophores, which are buried in the protein matrix. The three-dimensional,
well-defined architecture of the surrounding is a prerequisite for their function.
Excitation of the isolated chromophores leads only to a negligible light emission at
room temperature. Several processes competing with the radiative decay are respon-
sible for the quenching. To understand how nature has learned to suppress these
alternative pathways from the excited state in autofluorescent proteins, the molecular
dynamics as well as the influence of several amino acids in the interior of the protein
has to be analysed. We review the current status of the understanding of the non-
radiative decay mechanisms for the different fluorescent protein classes, i.e., colours.
Furthermore, we address what can be learned from fluorescence lifetime measure-
ments and how they can be exploited for analytical purposes such as fluorescence
lifetime imaging microscopy. Finally, we sketch the needs of increased fluorescence
quantum yields and present strategies to prolong the fluorescence lifetimes.
Keywords FLIM
Internal conversion
Photophysics
Protein dynamics
TCSPC
Contents
1 Principles of Fluorescence Decays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
1.1 Introduction into the Photophysics of a Fluorophore: The Jablonski Scheme . . . . . . . 70
1.2 Einstein Factors: Absorption, Spontaneous and Stimulated Emission . . . . . . . . . . . . . . . 72
G. Jung ( * ), B. Hotzer, and S.K. Veettil
Biophysical Chemistry, Saarland University, Campus B2 2, 66123 Saarbrucken, Germany
e-mail: g.jung@mx.uni-saarland.de
A. Brockhinke and S. Schwedler
Physical Chemistry 1, University of Bielefeld, Postfach 10 01 31, 33501 Bielefeld, Germany
T. Gensch
Institute of Structural Biology and Biophysics 1 (Cellular Signaling, ISB-1), Forschungszentrum
J
ulich, 52425 J
ulich, Germany
Search WWH ::




Custom Search