Simulating FRET from tryptophan: Is the rotamer model correct?

Beitrag in einer Fachzeitschrift

Details zur Publikation

Autorinnen und Autoren: Beierlein F, Othersen O, Lanig H, Schneider S, Clark T
Zeitschrift: Journal of the American Chemical Society
Verlag: American Chemical Society
Jahr der Veröffentlichung: 2006
Band: 128
Heftnummer: 15
Seitenbereich: 5142-5152
ISSN: 0002-7863


We present a computational model study designed to simulate the results of time-resolved fluorescence spectra of tryptophan in proteins. In such measurements, the occurrence of more than one fluorescence lifetime is generally attributed to the existence of several tryptophan rotamers and/or structural conformations of the protein structure. The protein system we chose for this initial study is the tetracycline repressor (TetR), an interesting model system for the investigation of the mechanisms of transcriptional regulation. Fluorescence resonance energy transfer (FRET) from tryptophan to tetracycline is frequently observed in complexes of the TetR with the antibiotic tetracycline. We use a combined classical/quantum mechanical approach to model the structure and the spectroscopic properties of the TetR-tetracycline complex. A classical molecular dynamics simulation provides input geometries for semiempirical quantum mechanical/molecular mechanical (OM/MM) single-point configuration interaction (CI) calculations, which are used to calculate tryptophan vertical absorption and fluorescence energies and intensities as well as relative FRET rate constants. These rate constants together with the Einstein coefficients for spontaneous emission and an assumed rate for nonradiative deactivation allow us to simulate fluorescence decay curves with and without FRET and for the entire ensemble as well as for individual rotamers. Our results indicate that the classical "rotamer model", used to explain the multiexponential fluorescence-decay curves of time-resolved tryptophan emission spectra, can be extended to systems with FRET acceptors present in the protein matrix but that the interpretation of the fitted lifetimes is different to that usually used.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Beierlein, Frank Dr.
Clark, Timothy apl. Prof. Dr.
Lanig, Harald PD Dr.
Exzellenz-Cluster Engineering of Advanced Materials
Schneider, Siegfried Prof. Dr.
Naturwissenschaftliche Fakultät


Beierlein, F., Othersen, O., Lanig, H., Schneider, S., & Clark, T. (2006). Simulating FRET from tryptophan: Is the rotamer model correct? Journal of the American Chemical Society, 128(15), 5142-5152.

Beierlein, Frank, et al. "Simulating FRET from tryptophan: Is the rotamer model correct?" Journal of the American Chemical Society 128.15 (2006): 5142-5152.


Zuletzt aktualisiert 2018-08-08 um 10:53