title: Kinetic multichannel spectroscopy of biological molecules: decomposition of the spectral matrix.
abstract: The time-resolved difference spectra after flash excitation of various biological molecules are measured on a gated optical multichannel analyzer. Electron transfer between the photoactive covalent label thiouredopyrene-trisulfonate and the heme of cytochrome c and the photocycle of the E204Q mutant bacteriorhodopsin are studied. The spectral matrices containing consecutive difference spectra are analyzed to reveal the reaction kinetics and individual component spectra. Singular value decomposition combined with stoichiometric analysis and self-modeling is demonstrated as a tool for successful dissection of the matrix, despite the difficulties arising from broad, featureless, overlapping spectra and the overlapping kinetics of the components.
authors.affiliation: Institute of Biophysics, Biological Research Center of the Hungarian Academy of Sciences, P.O. Box 521, Szeged H-6701, Hungary. zimanyi@nucleus.szbk.u-szeged.hu
authors.forename: László
authors.initials: L
authors.lastname: Zimányi
mesh_terms: D000818:Animals; D001436:Bacteriorhodopsins / Q000737:chemistry; D003574:Cytochrome c Group / Q000737:chemistry; D003580:Cytochromes / Q000737:chemistry*; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D013053:Spectrophotometry / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D003574:Cytochrome c Group; D003580:Cytochromes; D001436:Bacteriorhodopsins