氧化硅片表面配基疏水性及含量对蛋白质吸附行为的影响

Effects of Hydrophobicity and Content of Ligands on Silica Surface on Adsorption Behaviors of Proteins

采用双偏振极化干涉分析技术研究了氧化硅片表面配基疏水性及含量对蛋白质质吸附行为的影响,用3种不同疏水性配基3-(氨丙基)三乙氧基硅烷(APTES)、3-(N-甲氨基丙基)三甲氧基硅烷(MAPTMS)和3-(N,N-二乙基氨丙基)三甲氧基硅烷(DAPTMS)修饰氧化硅片,通过修饰时间控制硅片表面配基含量,研究了配基疏水性对牛血清白蛋白质(BSA)的影响和配基含量(N含量)对BSA、细胞色素C和糜蛋白酶吸附行为的影响.结果表明,BSA在疏水性最强的DAPTMS修饰的氧化硅表面吸附量及吸附动力学常数最大,分别为1.371 ng/mm2和0.056 s-1;DAPTMS含量对3种蛋白质吸附的影响与蛋白质疏水性密切相关,疏水性中等的BSA和细胞色素C为单分子层吸附,吸附量随N含量增加先增大后减小,N含量2.1%时吸附量最大,分别为16.9和60.2 nmol/m2.疏水性较强的糜蛋白酶为多分子层吸附,吸附量随N含量增大而减小,N含量1.1%时吸附量及吸附动力学常数分别为78.6 nmol/m2和0.040 s-1.

The effects of hydrophobicity and ligand content on adsorption behaviors of proteins were investigated using dual polarization interferometry （DPI）. The silica （DPI chip） surfaces were modified with 3-（aminopropyl） triethoxysilane （APTES）, 3-（methacryloxy propyl） trimethoxysilane （MAPTMS） and 3-（diethylaminopropyl） trimethoxysilane （DAPTMS）. The content of ligand on DPI chip was controlled by controlling modification time. The adsorption behaviors of bovine serum albumin （BSA）, Cytochrome C and chymotrypsin on different surfaces were analyzed. The results indicated that the adsorption capacity of BSA on surface modified with DAPTMS was higher than that modified with APTES and MAPTMS. The adsorption capacity of BSA and adsorption kinetic constant were 1.371 ng/mm^2 and 0.056 s^-1, respectively. Ligand content affected protein adsorption, which is associated with protein hydrophobicity. BSA and Cytochrome C, as mid-hydrophobic model protein, formed a single layer on DPI surface. The adsorbed capacity of proteins climbs up and then declines with the increase of ligand content. The maximum adsorption capacity was 16.9 nmol/m^2 for BSA and 60.2 nmol/m^2 for Cytochrome C with N content as 2.1%. Chymotrypsin, as higher hydrophobic model, formed the multi-layer on DPI surface. The adsorption capacity and kinetic constant decrease with the density increases. The max adsorption capacity was 78.6 nmol/m^2 and the max kinetic constant was 0.040 s^-1 on DPI chip with N content as 1.1%.