title: Protein energy landscapes determined by five-dimensional crystallography.
abstract: Free-energy landscapes decisively determine the progress of enzymatically catalyzed reactions [Cornish-Bowden (2012), Fundamentals of Enzyme Kinetics, 4th ed.]. Time-resolved macromolecular crystallography unifies transient-state kinetics with structure determination [Moffat (2001), Chem. Rev. 101, 1569-1581; Schmidt et al. (2005), Methods Mol. Biol. 305, 115-154; Schmidt (2008), Ultrashort Laser Pulses in Medicine and Biology] because both can be determined from the same set of X-ray data. Here, it is demonstrated how barriers of activation can be determined solely from five-dimensional crystallography, where in addition to space and time, temperature is a variable as well [Schmidt et al. (2010), Acta Cryst. A66, 198-206]. Directly linking molecular structures with barriers of activation between them allows insight into the structural nature of the barrier to be gained. Comprehensive time series of crystallographic data at 14 different temperature settings were analyzed and the entropy and enthalpy contributions to the barriers of activation were determined. One hundred years after the discovery of X-ray scattering, these results advance X-ray structure determination to a new frontier: the determination of energy landscapes.
authors: Physics Department, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
authors: Marius
authors: M
authors: Schmidt
authors: Vukica
authors: V
authors: Srajer
authors: Robert
authors: R
authors: Henning
authors: Hyotcherl
authors: H
authors: Ihee
authors: Namrta
authors: N
authors: Purwar
authors: Jason
authors: J
authors: Tenboer
authors: Shailesh
authors: S
authors: Tripathi
mesh_terms: D001419:Bacteria / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray / Q000379:methods; D007700:Kinetics; D020283:Photoreceptors, Microbial / Q000737:chemistry*; D011487:Protein Conformation; D013816:Thermodynamics
chemical_list: D001426:Bacterial Proteins; D020283:Photoreceptors, Microbial; C050162:photoactive yellow protein, Bacteria
keywords: chemical kinetics; five-dimensional crystallography; photoactive yellow protein; time-resolved crystallography; time-resolved microspectrophotometry