离子交换配基密度对蛋白质吸附行为的影响

Effect of the ion exchange chromatography ligand density on the absorption behavior of proteins

利用双偏振极化干涉测量仪(DPI)研究了离子交换配基密度对蛋白质吸附行为的影响。用N,N-二乙基-3-氨基丙基三甲氧基硅烷(DAPTMS)对DPI芯片进行修饰,利用X射线光电子能谱表征了芯片上配基密度的差异。以溶菌酶、细胞色素C、糜蛋白酶、牛血清白蛋白和免疫球蛋白为模型蛋白,利用DPI研究了5种蛋白质在不同配基密度界面上吸附量、吸附密度和空间形态。结果表明,随着配基密度的增加,蛋白在界面上的吸附量、吸附密度随之增加,起始吸附速率随之增大;蛋白的空间形态与配基密度密切相关,特别是免疫球蛋白,蛋白层厚度远小于其分子直径,空间形态发生变化。证明配基密度是影响界面上蛋白质吸附量、吸附密度和空间形态等吸附行为的关键因素。

The effect of ligand density on the adsorption behavior of proteins was investigated using dual polarization interferometry（ DPI）. The sensor chips of DPI were modified with 3-aminopropy-l-triethoxysilane（ DAPTMS）. The ligand densities on the modified chips were compared using X-ray photoelectron spectroscopy. Lysozyme,myoglobin,chymotrypsin,bovine serum albumin and immunoglobulin were used as model proteins. The adsorption behaviors of five proteins,such as adsorption amount,adsorption density and spatial structure,on the modified chips were characterized using DPI. It was found that with the increase of ligand density,the adsorption amount and density of proteins at the interface increased. Meanwhile,the initial adsorption rate grew. The spatial structure of proteins,especially immunoglobulin,was closely related with ligand density. The thickness of adsorption immunoglobulin layer was much smaller than the molecular diameter. The results indicated that the ligand density on the modified chip affected the amount,density and spatial structure of proteins on the interfaces.