title: Tryptophan rotamers as evidenced by X-ray, fluorescence lifetimes, and molecular dynamics modeling.
abstract: We investigated the native-state dynamics of the Bacillus caldolyticus cold-shock protein mutant Bc-Csp L66E, using fluorescence and appropriate molecular dynamics methods. Two fluorescence lifetimes were found, the amplitudes of which agree very well with tryptophan rotamer populations, obtained from parallel tempering calculations. Rotamer lifetimes were predicted by transition-state theory from high-temperature simulations. Transition pathways were extracted from the transition rates between individual rotameric states. The molecular dynamics also reveal the loop fluctuations in the native state.
authors.affiliation: Laboratory of Quantum Chemistry, University of Leuven, Leuven, Belgium.
authors.forename: Samuel L C
authors.initials: SL
authors.lastname: Moors
authors.forename: Mario
authors.initials: M
authors.lastname: Hellings
authors.forename: Marc
authors.initials: M
authors.lastname: De Maeyer
authors.forename: Yves
authors.initials: Y
authors.lastname: Engelborghs
authors.forename: Arnout
authors.initials: A
authors.lastname: Ceulemans
mesh_terms: D020106:Acrylamide / Q000737:chemistry; D001407:Bacillus / Q000235:genetics / Q000378:metabolism*; D001703:Biophysics / Q000379:methods; D007700:Kinetics; D008958:Models, Molecular; D015233:Models, Statistical; D009154:Mutation; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D013997:Time Factors; D014364:Tryptophan / Q000737:chemistry*; D014965:X-Rays
chemical_list: D012997:Solvents; D020106:Acrylamide; D014364:Tryptophan