【作者】 英晓光；

【导师】 成国祥；

【作者基本信息】 天津大学 ， 材料学， 2010， 博士

【摘要】 蛋白质大分子印迹聚合物微球材料在许多科研领域已得到越来越多的重视.大分子印迹凝胶聚合物体系的重结合行为涉及构象的改变及适配等不同于传统小分子印迹体系的过程,使得该体系的重结合行为相似于生命体系识别的某些步骤,但也有其本质区别.蛋白质大分子的印迹方法须考虑到蛋白质分子自身的特点给印迹聚合物带来的影响,即体积效应、多官能团及构象多变等性质.选用含水量高、网孔尺度适合、官能团含量丰富、溶胀性能良好的水凝胶类基材已逐渐成为研究者的共识.适用于蛋白质类印迹材料的计算方法和理论模型包括Langmuir单层吸附模型、Scatchard分析法,以及由我组提出的目标作用模式原理和印迹诱导适配模型等.本研究首先采用两种新型双水相成球方法制备了蛋白质印迹海藻酸钙凝胶聚合物微球,研究了各种制备条件对微球形貌、尺寸、分布及力学性能的影响,获得了可兼顾产量和均一性的最佳操作工艺.研究了蛋白质溶液的聚集状态及其影响因素,总结归纳并获得了一系列蛋白质聚集态所需试剂量及配制控制条件.在对印迹诱导适配行为的研究中,采用不同交联密度的聚合物作为印迹基材,研究了重结合速率常数随着交联密度及溶胀度的变化规律.在此基础上建立“印迹诱导适配模型”并引入参量“适配性参数”作为衡量基材适配行为的手段.通过理论计算证实了凝胶印迹体系适配行为的存在及可预测性.针对蛋白质模板进行了以下方面的研究:运用Scatchard分析法研究了不同聚集态组分的蛋白质溶液的重结合行为;利用一级连串反应方程重点研究了二聚体相关的重结合反应,建立了重结合量回归方程式;利用Arrhenius公式推导出单分子、二聚体及二者混合体系的重结合量方程和重结合自由能方程;得出了“印迹诱导适配模型的本质是熵补偿机制(entropic/enthalpic compensation mechanism)”的重要结论.印迹聚合物制备的最终目的是实现特异重结合性.本研究制备了溶菌酶及细胞色素C分子双模板印迹凝胶微球用以研究重结合选择性.提出“相对印迹效率”参量用以表征单印迹微球在单组分及双组分溶液中的特异重结合性能.通过紫外分光光度计、电导率仪及离子交换色谱等手段证实,单印迹微球在双组分溶液中的相对印迹效率可高达2.92和3.91,即具有良好的选择性重结合效果.更多还原

【Abstract】 The protein macromolecularly imprinted polymeric microspheres have become more and more attractive in many fields. The rebinding within macromolecularly imprinted gel polymer systems involves conformational changing and fitting that are different from classical molecularly imprinted materials. This makes it resemble some of the steps in recognition of life system but also possess essential differences.The operations of protein imprinting should take into account the impact of the protein properties, i.e. the volume effect, multi-functional groups and conformational instability and so on. It has become a consensus of the researchers that hydrogels with high water content, suitable mesh scale, numerous functional groups and satisfying swelling properties be used as a new kind of imprinted materials. Calculation and theoretical models applicable for protein imprinting materials are Langmuir monolayer adsorption model, Scatchard analysis, as well as the principle of target interaction mode and imprinting induced fitting model proposed by our group.In this study protein imprinted calcium alginate microspheres were prepared by two novel aqueous suspending methods. The experimental conditions affecting microspheres’morphology, shape distribution and mechanical properties were studied. Optimum preparation program have been made giving consideration to both sides of yield and uniformity. Then protein aggregations and their influencing factors were studies and the required reagent quantity and solution conditions were also investigated.The imprinting matrix was made of gel polymer with different crosslinking density. The imprinting induced fitting behavior was studied by investigating rebinding speed variation as the function of crosslinking density and swelling degree. The imprinting induce-fit model was established accordingly and parameter“fitting factor”was introduced to measure the fitting behavior of the matrix. The existence and predictability of fitting behavior of hydrogel imprinting systems were confirmed by theoretical calculations.Researches in view of the protein template have been conducted from the following aspects. The rebinding in protein solutions with different aggregating states was studied by Scatchard analysis. The dimer related rebinding was studied by means of first order consecutive reaction formula and the regression equation of rebinding quantity was established. The rebinding quantity and rebinding free energy formula of single molecule, dimer, and mixed system were developed from Arrhenius equation. Then an important conclusion was proposed:“the imprinting induced fitting model’s essence is the entropic/enthalpic compensation mechanism”.The ultimate objective of imprinted polymer materials is specific rebinding. In this study the lysozyme and cytochrome C were templated in hydrogel microspheres with the aim of studying rebinding selectivity. The“relative imprinting efficiency (IEr)”had been proposed to estimate rebinding specificity of imprinted beads in single and double component solutions. As characterized by UV spectrophotometer, conductivity meter and ionic exchange chromatograph, the IEr of mono-imprinted microspheres in double component solutions may reach as high as 2.92 and 3.91, i.e. the selective rebinding is satisfying.更多还原