Study On The Partition Properties Of Bovine Serum Albumin In Aqueous Two-phase System

Characteristics of the aqueous two-phase and its extraction principle were introduced.A review was given on influence factor of molecules'partition,especially on domestic and international research.Bovine serum albumin which has wide application, mature research,excelent heat stability and acquire easily was studied as research material by reviewing its partition properties in PEG/dextran system, PEG-C₂H₅OH-(NH₄)₂SO₄ combined organic solvent system and PEG/Dex-OLL-Ac system.The phase diagram which formed by four molecular weight of PEG and dextran are studied,at the same time,The influence of molecular weight of PEG, phase compositions concentration,neutral salt species and concentration,pH values,organic solvent and surfactant on the partition properties of BSA was investigated in PEG/dextran aqueous two-phase system.It was shown that the partition coefficient of BSA was the least when the system is PEG6000 9ï¼…-dextran 10ï¼…with pH values and NaC1 concentration were 7.0 and 0.2mol/L(phosphate concentration was 0.01 mol/L), and the value was 0.0116.This condition was the best operation condition.The influence of C₂H-5OH concentration, molecular weight of PEG,NaCl concentration and pH values on the partition properties of BSA in PEG-C₂H₅OH-(NH₄)₂SO₄ combined organic solvent aqueous two-phase system was investigated.It was shown that partition coefficients of BSA has reduced observably and partition of BSA was more steady in this system compare with in PEG/(NH₄)₂SO₄ system.Dex-OLL-Ac,Dex-OLL-MEE are two modified productions by two strategies grafting L-lactic acid oligomers (OLL) to dextran.Drawing the phase diagram of PEG6000/Dex-OLL-Ac system.It was shown that this phase diagram accords with the rule of phase formation of polymer/polymer aqueous two-phase system.It has lower separation concentration comparing with PEG/Dex system. Using PEG6000/Dex-OLL-Ac system which has been chosen to part BSA. It was shown that partition coefficient of BSA became smaller when molecular weight and concentrateion of PEG become larger.Under the influence of pH values, partition coefficient was the least at the equipotential point (pI=7.0).Partition coefficient of BSA has reduced obviously in this system comparing with PEG/Dex system when studied in each influence factor.