title: Chemical dynamics in proteins: the photoisomerization of retinal in bacteriorhodopsin.
abstract: Chemical dynamics in proteins are discussed, with bacteriorhodopsin serving as a model system. Ultrafast time-resolved methods used to probe the chemical dynamics of retinal photoisomerization in bacteriorhodopsin are discussed, along with future prospects for ultrafast time-resolved crystallography. The photoisomerization of retinal in bacteriorhodopsin is far more selective and efficient than in solution, the origins of which are discussed in the context of a three-state model for the photoisomerization reaction coordinate. The chemical dynamics are complex, with the excited-state relaxation exhibiting a multiexponential decay with well-defined rate constants. Possible origins for the two major components are also discussed.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: F
authors.initials: F
authors.lastname: Gai
authors.forename: K C
authors.initials: KC
authors.lastname: Hasson
authors.forename: J C
authors.initials: JC
authors.lastname: McDonald
authors.forename: P A
authors.initials: PA
authors.lastname: Anfinrud
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000378:metabolism; D004224:Diterpenes; D019617:Halobacterium salinarum / Q000737:chemistry / Q000378:metabolism; D007536:Isomerism; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D011487:Protein Conformation; D012172:Retinaldehyde / Q000737:chemistry* / Q000378:metabolism; D013057:Spectrum Analysis; D013816:Thermodynamics
chemical_list: D004224:Diterpenes; C031338:13-cis-retinal; D001436:Bacteriorhodopsins; D012172:Retinaldehyde