Tong X D, Sun Y
Department of Biochemical Engineering, Tianjin University, Tianjin 300072, People's Republic of China.
Biotechnol Prog. 2001 Jul-Aug;17(4):738-43. doi: 10.1021/bp010054s.
Magnetic colloidal particles were prepared by a coprecipitation method. The particles were composed of nanometer-sized superparamagnetic Fe(3)O(4) particles stabilized by lauric acid. Then, magnetic agar gel beads were produced by a water-in-oil emulsification method using a mixture of agar solution and the magnetic colloidal particles as the aqueous phase. A reactive triazine dye, Cibacron blue 3GA (CB), was coupled to the gel to prepare an agar-based magnetic affinity support (MAS) for protein adsorption. The support showed good magnetic responsiveness in a magnetic field. Bovine serum albumin (BSA) was used as a model protein to test adsorption equilibrium and kinetic behavior of the MAS. The adsorption equilibrium of BSA to the MAS was described by the Langmuir-type isotherm. Adsorption capacity of the MAS for BSA was up to 25 mg/mL at a CB coupling density of 1.6 micromol/mL. The effect of ionic strength on BSA adsorption was complex, exhibiting a maximum capacity at an ionic strength of 0.06 mol/L. The adsorption of BSA to the MAS was also influenced by pH. Uptake rate of BSA to the MAS was analyzed using a pore diffusion model. The pore diffusion coefficient was estimated to be 1.75 x 10(-11) m(2)/s. Finally, recycled use of the MAS demonstrated the stability of the MAS in protein adsorption and magnetic responsiveness.
通过共沉淀法制备磁性胶体颗粒。这些颗粒由月桂酸稳定的纳米级超顺磁性Fe(3)O(4)颗粒组成。然后，以琼脂溶液和磁性胶体颗粒的混合物为水相，通过油包水乳化法制备磁性琼脂凝胶珠。将活性三嗪染料Cibacron blue 3GA（CB）偶联到凝胶上，制备用于蛋白质吸附的琼脂基磁性亲和载体（MAS）。该载体在磁场中表现出良好的磁响应性。以牛血清白蛋白（BSA）为模型蛋白，测试MAS的吸附平衡和动力学行为。BSA对MAS的吸附平衡用Langmuir型等温线描述。在CB偶联密度为1.6 μmol/mL时，MAS对BSA的吸附容量高达25 mg/mL。离子强度对BSA吸附的影响较为复杂，在离子强度为0.06 mol/L时表现出最大容量。BSA对MAS的吸附也受pH值影响。用孔扩散模型分析了BSA对MAS的摄取速率。孔扩散系数估计为1.75×10(-11) m(2)/s。最后，MAS的循环使用证明了其在蛋白质吸附和磁响应性方面的稳定性。
