题名表面配基和蛋白质性质对固-液界面蛋白质吸附的影响
作者余瑾瑜
学位类别硕士
答辩日期2016-07
授予单位中国科学院研究生院
授予地点北京
导师苏志国 ; 张贵锋
关键词动力学常数 蛋白质吸附 配基相对含量 双偏振光干涉分析仪
学位专业生物工程
中文摘要

论文以双偏振光干涉分析仪(Dual Polarization Interferometry,DPI)为主要手段,结合蛋白质分子结构特征,研究了蛋白质在固-液界面的吸附现象,并进一步探索了固体表面性质与蛋白质性质对吸附的影响作用,旨在为大分子蛋白质的高效分离技术提供理论基础。实验先通过将氨基硅烷修饰剂与氧化硅固相表面进行偶联,制备了带有三种配基的界面,用DPI研究了配基性质对蛋白质吸附的影响;通过控制反应时间得到不同相对含量配基的固相表面,研究了配基相对含量对蛋白质吸附行为的影响,论文主要得到以下研究结果: (1)以牛血清白蛋白(Bull Serum Albmin,BSA)、人免疫球蛋白(Human Immunoglobin G,hIgG)为模型蛋白,研究了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)三种不同配基修饰界面对蛋白质吸附行为的影响。DPI结果表明BSA在疏水性较强的DAPTMS修饰配基表面具有高动态平衡吸附量及吸附动力学常数,分别达到1.371 ng/mm2和0.056 s-1;hIgG在带正电荷最多的APTES上的动态平衡吸附量及吸附动力学常数最大,分别为1.643 ng/mm2和0.0372 s-1。 (2)用DPI考察了配基相对含量对BSA、hIgG、细胞色素C、溶菌酶和糜蛋白酶的吸附行为的影响。结果表明,在制备的配基相对含量范围内,糜蛋白酶主要是形成多分子层吸附,其动态平衡吸附量和动力学常数随配基相对含量的增加而减小;其余四种蛋白形成单分子层吸附,随配基相对含量的增加,动态平衡吸附量均表现为先增加后降低的趋向。对蛋白质尺寸较小的细胞色素C和溶菌酶而言,吸附动力学常数也呈现出先增后减的规律;对蛋白质尺寸较大的BSA和hIgG来说动力学常数的规律与动态平衡吸附量的规律并不一致;BSA的吸附速率常数随配基相对含量的增加在0.008~0.010 s-1之间变化不大,hIgG的吸附动力学常数随配基相对含量的增加而先减小后增大。 (3)以BSA、hIgG、细胞色素C、溶菌酶和糜蛋白酶五种蛋白为模型,研究了蛋白质的尺寸、带电性质及疏水性质对蛋白质吸附行为的影响。研究发现疏水性系数较高(0.75)、带负电荷面积较少(9.36 nm2)的糜蛋白酶形成了多分子层吸附,具有高吸附量和动力学常数,在五种蛋白质中吸附量达到78.6 nmol/m2,吸附动力学常数达到0.040 s-1。其余四种蛋白质吸附形成的均为单分子层,动态吸附平衡量大小为细胞色素C(43.4 nmol/m2)>溶菌酶(28.8 nmol/m2)>BSA(15.2 nmol/m2)>hIgG(7.3 nmol/m2)其变化与蛋白质分子所带负电荷面积及蛋白质分子尺寸的变化趋势一致,表明蛋白质的平衡吸附量大小主要受到了静电力以及吸附时空间位阻的影响;动力学常数的大小为hIgG(0.020 s-1)>溶菌酶(0.019 s-1)>BSA(0.010 s-1)>细胞色素C(0.080 s-1),其变化与蛋白质的疏水系数变化趋势一致,说明蛋白质的吸附主要受到作用范围较大的疏水作用力的影响,而净电荷量对吸附行为的影响不显著。

英文摘要

In this research, dual polarization interferometry(DPI) was utilized as the main method to investigate protein adsorption behaviors at solid-liquid interface combing with the analysis of protein structure. The effects of properties of solid surface and protein on adsorption behaviors were further investigated in order to provide theoretical basis for high-efficiency separation technology of biological macromolecules. It could provide some reference data for high-efficiency separation technique. We first modified silica surfaces with 3 different aminosilanes to obtain surfaces with different ligand. On this basis, the effects of ligand properties on protein adsorption behavior were investigated. In addition, different relative amounts of ligand on solid surfaces were obtained by controlling the reaction time. Based on this, we analyzed the effect of relative amount of ligand on protein behavior.The following results were obtained: (1) Bull serum albumin (BSA) and human immunoglobin G (hIgG) were used as model proteins to investigate the effect of ligand type on protein adsorption behavior. The solid sufaces were modified with 3-(aminopropyl) triethoxysilane (APTES), 3-(methacryloxy propyl) trimethoxysilane (MAPTMS) and 3-(diethylaminopropyl) trimethoxysilane (DAPTMS). The DPI results showed that BSA obtained larger amount of adsorbe protein and kinetic constant on more hydrophobic DAPTMS modified surface. The amount of adsorbed protein is 1.371 ng/mm2 while the kinetic constant is 0.056 s-1. hIgG tended to adsorb more and faster on APTES modified surface which contains more positive charge. The amount of adsorbed protein is 1.643 ng/mm2 while the kinetic constant is 0.0372 s-1. (2) BSA, hIgG, cytochrome c, lysozyme and chymotrypsin were used as model proteins to investigate the effect of relative amount of ligand on protein adsorption behaviors utilizing DPI. Under the range of investigated relative amounts of ligand, the result showed that chymotrypsin tended to form the multi-layer on surface. The adsorbed amount and kinetic constant increased with the increase of relative amount of ligand. The other four proteins formed single layer on surface. The adsorbed amount climbed up and then declined with the increase of relative amount of ligand. The kinetic constants had the same variation trend with adsorbed amount for small-size cytochrome c and lysozyme. For BSA and hIgG with larger size, the variation trends were not in agreement with adsorbed amount. The kinetic constants of BSA changed little in the range of 0.008~0.010 s-1 while the kinetic constants of hIgG decreased at first and then increased with the increase of relative amount of ligand. (3) BSA, hIgG, Cytochrome C, lysozyme and chymotrypsin were employed as model proteins to investigate the effect of properties of protein size, charge and hydrophobicity on adsorption behaviors. The research found that chymotrypsin which had higher hydrophobic coefficient (0.75) and less negatively charged area (9.36 nm2) formed multilayer adsorption. Higher adsorbed amount and kinetic constant were obtained among 5 model proteins. The adsorption amount reached 78.6 nmol/m2 while the kinetic constant attained 0.040 s-1. The other 4 proteins formed single-layer. The adsorbed amounts from large to small were: Cytochrome C (43.4 nmol/m2) > lysozyme (28.8 nmol/m2) > BSA (15.2 nmol/m2) > hIgG (7.3 nmol/m2). It was in agreement with the order of negatively charged area and protein size, indicating that the adsorption amount was mainly affected by electrostatic force and steric hindrance. Kinetic constants sorted by size were: hIgG (0.020 s-1) > lysozyme (0.019 s-1) > BSA (0.010 s-1) > Cytochrome C (0.080 s-1). The trend was in agreement with the trend of hydrophobic coefficient, suggesting that it was the hydrophobic interaction that affected adsorption behavior most other than total charge of protein.

语种中文
内容类型学位论文
源URL[http://ir.ipe.ac.cn/handle/122111/22931]  
专题过程工程研究所_研究所(批量导入)
推荐引用方式
GB/T 7714
余瑾瑜. 表面配基和蛋白质性质对固-液界面蛋白质吸附的影响[D]. 北京. 中国科学院研究生院. 2016.
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