Probing protein aggregation by time-resolved fluorescence during beta-lactoglobulin crystal growth.
We have used the fluorescence anisotropy (FA) decay of retinol bound to bovine beta-lactoglobulin to monitor the time evolution of protein aggregation during the early stages of crystal growth. With this approach we have followed the formation of aggregates at different concentrations of ammonium sulfate, the precipitant used for crystallization. The average aggregation number is found to depend on precipitant concentration, and to be restricted to small numbers ranging from 2 to 5, also in the presence of visible growing crystals. The effect of particle distribution and of low probe-to-protein saturation on the FA response is also discussed in detail.
Collini
Maddalena
M
Istituto Nazionale per la Fisica della Materia and Dipartimento di Fisica, Università di Milano-Bicocca, Piazza della Scienza 3, 20126 Milan, Italy.
Leo
Barbara
B
Baldini
Giancarlo
G
Monaco
Hugo L
HL
Galliano
Monica
M
D000645:Ammonium Sulfate / Q000494:pharmacology; D000818:Animals; D016880:Anisotropy; D002417:Cattle; D003460:Crystallization; D019281:Dimerization; D007782:Lactoglobulins / Q000737:chemistry*; D008027:Light; D015233:Models, Statistical; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013997:Time Factors; D014801:Vitamin A / Q000737:chemistry
D007782:Lactoglobulins; D014801:Vitamin A; D000645:Ammonium Sulfate