Study on the mechanism of binding of tamoxifen and β-lactoglobulin

Objective To explore the possibility of β-lactoglobulin (BLG) as carrier of tamoxifen.

Methods The binding mechanism of BLG and tamoxifen was studied by spectroscopic technique.

Results Tamoxifen would lead to the fluorescence quenching of BLG, and its K_q value was much higher than the maximal K_q value of the dynamic quenching constant (2.0×10¹⁰ mol/(L·s). The quenching constant values were different under different pH values, and the values of thermodynamic parameters △H and △S were greater than 0. BLG can be combined with tamoxifen to form BLG-tamoxifen complex, and the endothermic process took hydrophobic force as the main force. Tamoxifen and BLG had different binding patterns under acidic and alkaline conditions, which mainly depended on the opening and closing state of the EF ring of BLG.

Conclusion BLG has the ability to bind tamoxifen, which shows the potential value of BLG as a carrier of insoluble drugs.