离子强度和溶质浓度对蛋白质在Q Sepharose FF中吸附动力学的影响

采用孔扩散模型, 模拟不同盐浓度和不同蛋白质初始浓度条件下，吸附牛血清白蛋白(BSA)的动态吸附曲线并获得孔扩散系数;考察了离子强度和溶质浓度对蛋白质在阴离子交换剂Q Sepharose FF中吸附动力学的影响.结果表明，蛋白质的孔扩散系数随初始浓度的增大而下降;在氯化钠浓度小于0.10 mol•L^-1的范围内，蛋白质的孔扩散系数随着盐浓度的增加而增大，但当盐浓度增大到0.15 mol•L^-1时又有所降低，表明存在着一个最佳的离子强度，使蛋白质的孔扩散系数最大.

Effect of ionic strength and protein concentration on protein adsorpotion kinetics in Q sepharose FF

The effect of ionic strength and initial protein concentration on the diffusion of bovine serum albumin (BSA) in an anion exchanger, Q Sepharose FF，was studied by batch adsorption experiments.The pore diffusion model was used to analyze the diffusive mass transfer of BSA in matrix pores.The pore diffusivity was determined by fitting the uptake curves of dynamic adsorption for BSA at different ionic strengths and initial protein concentrations,and the pore diffusion coefficient was obtained.The results showed that the pore diffusivity decreased with increasing initial protein concentration.The pore diffusivity increased with increasing NaCl concentration till 0.10 mol•L^-1.However, it became lower at a salt concentration of 0.15 mol•L^-1.This indicated that there existed an ionic strength where the pore diffusion coefficient exhibited its maximum value.