Steady-state and dynamic fluorescence titrations show that: (a) the complex between beta-lactoglobulin (BLG) and 1-anilinonaphthalene-8-sulfonate (ANS) displays a heterogeneous equilibrium with large changes in the binding strength vs. pH and ion concentration; and (b) the fluorescence response of bound ANS reveals two separate lifetimes that suggest two different sites (or binding modes). While steady-state fluorescence titrations yield effective values of the binding constant and of the bound ANS quantum efficiency, it is shown that, by combining steady-state fluorescence and lifetime decay of ANS, it is possible to give quantitative estimates of the association constants for each site. When heading from the acid (pH=2) to the native state (pH=6) the main result is a very large reduction of the effective binding constant. This and the results of titrations vs. ionic strength suggest that electrostatic interactions are a major contribution to ANS binding to BLG.
D'Alfonso, L., Collini, M., & Baldini, G. (1999). Evidence of heterogeneous 1-anilinonaphthalene-8-sulfonate binding to beta-lactoglobulin from fluorescence spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA, 1432, 194-202.
Citazione: | D'Alfonso, L., Collini, M., & Baldini, G. (1999). Evidence of heterogeneous 1-anilinonaphthalene-8-sulfonate binding to beta-lactoglobulin from fluorescence spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA, 1432, 194-202. |
Tipo: | Articolo in rivista - Articolo scientifico |
Carattere della pubblicazione: | Scientifica |
Titolo: | Evidence of heterogeneous 1-anilinonaphthalene-8-sulfonate binding to beta-lactoglobulin from fluorescence spectroscopy |
Autori: | D'Alfonso, L; Collini, M; Baldini, G |
Autori: | |
Data di pubblicazione: | 1999 |
Lingua: | English |
Rivista: | BIOCHIMICA ET BIOPHYSICA ACTA |
Appare nelle tipologie: | 01 - Articolo su rivista |