title: Resolution of heterogeneous fluorescence into component decay-associated excitation spectra. Application to subtilisins.
abstract: Direct and indirect methods are described to combine steady-state and picosecond time-resolved fluorescence decay data to generate decay-associated excitation spectra. The heterogeneous fluorescence from a fluorophore mixture that models protein fluorescence was resolved into individual component excitation spectra. The two methods were also used to determine the excitation spectra associated with each of the decay time components for the proteins subtilisin Carlsberg and BPN'. On the basis of associated spectra, the decay components of both proteins were assigned to individual (or groups of) emitting species. The two approaches used to generate the decay-associated excitation spectra are compared and their general application to protein fluorescence studies is discussed.
authors.affiliation: Division of Biological Sciences, National Research Council of Canada, Ottawa, Ontario.
authors.forename: K J
authors.initials: KJ
authors.lastname: Willis
authors.forename: A G
authors.initials: AG
authors.lastname: Szabo
authors.forename: J
authors.initials: J
authors.lastname: Drew
authors.forename: M
authors.initials: M
authors.lastname: Zuker
authors.forename: J M
authors.initials: JM
authors.lastname: Ridgeway
mesh_terms: D007700:Kinetics; D008433:Mathematics; D008962:Models, Theoretical; D013050:Spectrometry, Fluorescence / Q000379:methods; D013381:Subtilisins / Q000378:metabolism*; D014363:Tryptamines; D014443:Tyrosine
chemical_list: D014363:Tryptamines; D014443:Tyrosine; C035668:N-methyltryptamine; D013381:Subtilisins