Multiwavelength analysis of the kinetics of reduction of cytochrome aa3 by cytochrome c.
Some new approaches to the kinetic study of the reduction of cytochrome aa3 by cytochrome c are presented. The primary innovations are the use of a spectrometer which can acquire multiwavelength data as fast as every 10 microseconds, and the application of a variety of analytical methods which can utilize simultaneously all of the time-resolved spectral data. These techniques include singular value decomposition (SVD), deconvolutions based on pure Gaussian models for absorption peaks, deconvolutions based on isolated absorption spectra for the pure components, and simulations of SVD-deduced and actual experimental difference spectra. The reduction characteristics of the anaerobic resting enzyme can be distinguished from those of pulsed forms. In the former case, only two electrons can be bound by cytochrome aa3, whereas in the latter case complete reduction of the enzyme is achieved.
Hendler
R W
RW
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
Bose
S K
SK
Shrager
R I
RI
D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D002417:Cattle; D003198:Computer Simulation; D003574:Cytochrome c Group / Q000378:metabolism*; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism*; D006418:Heme / Q000031:analogs & derivatives / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008954:Models, Biological; D010084:Oxidation-Reduction; D013053:Spectrophotometry / Q000379:methods
D003574:Cytochrome c Group; C027728:heme a; D006418:Heme; D003576:Electron Transport Complex IV