Influence of magnetic field on extraction of model proteins in polyethylene glycol/magnesium sulfate aqueous two-phase system

摘要

Separation of molecules in aqueous two-phase systems (ATPS) depends on many factors, e.g. salt concentration, pH, polyethylene glycol (PEG) concentration and molecular weight. The aim of the study was to analyze partition of model proteins (lysozyme, bovine serum albumin and hemoglobin) depending on the magnetic field action and the factors mentioned above in PEG/MgSO_4 ATPS. Partition of these proteins studied always depended on PEG molecular weight, while salt concentration influenced only BSA and HGB separation. Two of the proteins tested, i.e. lysozyme and BSA showed high affinity to the PEG-rich-phase. The magnetic field significantly forced distribution of BSA and lysozyme to the phase rich in MgSO_4. Hemoglobin, which presented a tendency to accumulation in salt phase was not affected by the magnetic field. Thus, the influence of the magnetic field on protein partition in ATPS is a consequence of the properties of separated molecules, and rearranges of water dipoles and hydrogen bonds reshape.