title: Thermal stability of a flavoprotein assessed from associative analysis of polarized time-resolved fluorescence spectroscopy.
abstract: Upon gradually heating a particular mutant of the flavoprotein NADH peroxidase, it was found from the peculiar time-resolved fluorescence anisotropy pattern of the flavin prosthetic group (FAD) that, at elevated temperature, FAD is released from the tetrameric enzyme. Since in this case a mixture of free and enzyme-bound FAD contributes to the time-dependent fluorescence anisotropy, its analysis can only be accomplished by an associative fitting model, in which specific fluorescence lifetimes of both species are linked to specific correlation times. In this letter the general approach to the associative polarized fluorescence decay analysis is described. The procedure can be used for other flavoproteins to determine the temperature at which the onset of thermal denaturation will start, leading to release of the flavin prosthetic group.
authors.affiliation: Systems Analysis Department, Belarusian State University, Minsk 220050, Belarus.
authors.forename: A V
authors.initials: AV
authors.lastname: Digris
authors.forename: V V
authors.initials: VV
authors.lastname: Skakoun
authors.forename: E G
authors.initials: EG
authors.lastname: Novikov
authors.forename: A
authors.initials: A
authors.lastname: van Hoek
authors.forename: A
authors.initials: A
authors.lastname: Claiborne
authors.forename: A J
authors.initials: AJ
authors.lastname: Visser
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D013293:Enterococcus faecalis / Q000737:chemistry; D005420:Flavoproteins / Q000032:analysis*; D005454:Fluorescence Polarization / Q000379:methods*; D015233:Models, Statistical; D013696:Temperature; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D005420:Flavoproteins