Interactions between bovine serum albumin and oxidized sodium alginate in solution

This paper focuses on the interactions between oxidized sodium alginate (OSA) and bovine serum albumin (BSA) at the molecular level with the purpose to provide basic information for optimizing the biological utilization and pharmaceutical applications of OSA. The results revealed that OSA could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS), were also calculated. The process of binding was a spontaneous process in which Gibbs free energy change was negative. The distances between donor (BSA) and acceptor (OSA) were calculated to be 2.41, 2.54 and 2.84 nm for SA-BSA, 10% OSA-BSA and 30% OSA-BSA systems, based on Förster non-radiative energy transfer theory, respectively. The results of synchronous fluorescence spectra showed that binding of OSA with BSA cannot induce conformational changes in BSA. Meanwhile, the OSA with low degree of oxidization (DO% ≤ 30%) was non-cytotoxic. Therefore, OSA could be promising as a bioactive compound carrier.