木瓜蛋白酶动态膜结晶的实验研究

Experimental study on continuous osmotic membrane crystallization of papain

采用聚偏氟乙烯中空纤维微孔膜,考察结晶过程中蛋白质溶液和洗脱液流速的改变以及不同膜面积对溶剂跨膜通量及木瓜蛋白酶晶体尺寸的影响.结果表明:在以pH值为4.7的0.1 mol/L醋酸钠为缓冲溶液、1%的(NH4)3PO4为沉淀剂以及25%的MgCl2溶液作为洗脱液的木瓜蛋白酶动态膜结晶中,当有效膜面积为62.83 cm2,蛋白质溶液和洗脱液流速分别控制在4 744μm/s和1.37×104μm/s的高流速时膜组件的效率得到最大发挥,并得到了较大尺寸的木瓜蛋白酶晶体;当膜面积不同时,溶剂跨膜通量的衰减随着膜面积减小而趋于平缓.

The PVDF hollow fiber micro- porous membranes were employed to study the influences of such factors as flow velocities of protein solutions and stripping agent, membrane area on the process of membrane crystallization. It was found that, with 0.1 mol/L NaAc （pH= 4.7） as the buffer solution, 1% （NH4）3PO4 as precipitant and 25 % MgCl2 as stripping agent, when the membrane area was 62.83 cm2, the flow velocity of protein solutions was 4 744 μm/s and stripping agent was 1.37 × 104 μm/s, the largest size papain crystals were produced and the efficiency of the membrane was maximized. At the same time, the decrease of trans- mem- brane flux was tending to smooth with the reduction of the membrane area.