Molecular characterization of the β-lactoglobulin conjugated with fluorescein isothiocyanate: Binding sites and structure changes as function of pH

Protein conjugated with dyes is a method which can be used for analyzing food components. For example β-lactoglobulin (βlg) can be conjugated with amine-reactive dyes to form βlg-dye conjugates. In this study, the effect of pH on the conjugation of βlg with fluorescein isothiocyanate (FITC) was investigated using MALDI-TOF MS, LC-MS, dynamic light scattering (DLS) and fourier transform infrared spectroscopy (FTIR). The results showed that the...