Chemical dynamics in proteins: the photoisomerization of retinal in bacteriorhodopsin.
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.
Gai
F
F
Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
Hasson
K C
KC
McDonald
J C
JC
Anfinrud
P A
PA
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
D004224:Diterpenes; C031338:13-cis-retinal; D001436:Bacteriorhodopsins; D012172:Retinaldehyde