How do rotameric conformations influence the time-resolved fluorescence of tryptophan in proteins? A perspective based on molecular modeling and quantum chemistry
| Autor: | Yves Engelborghs, Samuel L. C. Moors, Abel Jonckheer, Arnout Ceulemans, Marc De Maeyer |
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| Rok vydání: | 2008 |
| Předmět: |
Models
Molecular Static Electricity Molecular Conformation Context (language use) Biochemistry Quantum chemistry Fluorescence Protein Structure Secondary Molecular dynamics Computational chemistry Computer Simulation Molecular Biology Conformational isomerism Quantitative Biology::Biomolecules Chemistry Time evolution Tryptophan Proteins Cell Biology General Medicine Solutions Kinetics Models Chemical Chemical physics Excited state Phase space Anisotropy Quantum Theory Thermodynamics Time-resolved spectroscopy |
| Zdroj: | Current proteinpeptide science. 9(5) |
| ISSN: | 1389-2037 |
| Popis: | We discuss the dynamics of tryptophan rotamers in the context of the non-exponential fluorescence decay in proteins. The central question is: how does the ground-state conformational heterogeneity influence the time evolution of tryptophan fluorescence? This problem is examined here from the theoretical perspective. Three methods at different levels of theory, and with different scopes and computational requirements are reviewed. The Dead-end elimination method is limited to side-chain dynamics and provides an efficient way to detect the stable tryptophan rotamers in a protein. Its application to the study of heterogeneous emission characteristics is illustrated. Molecular dynamics is aimed at the full phase space of the macromolecule in solution, but must rely on classical force fields and laws of evolution. We examine to what extent the molecular mechanics paradigm yields sufficiently accurate thermodynamic results, and what are the possible kinetic implications. Finally Quantum Chemistry is the only theoretical method that allows a direct assessment of the excited states. It is necessarily restricted to small molecular systems, and thus must be used in a hybrid combination with classical methods and electrostatic models. So far understanding of the emitting state has greatly progressed as a result of these calculations, but the actual treatment of the photophysical decay processes at the quantum level has not yet really started. |
| Databáze: | OpenAIRE |
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