【作者】 唐嘉英；

【导师】 应汉杰；

【作者基本信息】 南京工业大学 ， 生物化工， 2006， 硕士

【摘要】 目前,对多肽类的研究已经逐渐拓展到各个方面,研究对象也从传统的多肽激素延伸到多种用途的小肽类。传统的小肽分离纯化多使用反相色谱法和凝胶层析法,这两种方法在扩大生产方面都存在着不同程度的问题。传统常用的凝胶介质由于机械强度较差且价格昂贵,在扩大生产规模方面的应用受到很大限制。本研究引入小分子分离的理念,选用物化稳定性高、吸附选择性好、再生简便、解吸条件温和、使用周期长、适用于工业化生产的大孔树脂作为分离介质,选取TP5为模型肽,采用Langmuir吸附等温方程,利用规划求解,考察了pH值、起始溶液浓度,温度,搅拌转速等因素对多肽吸附平衡的影响,并为动力学研究提供一些基础数据。研究发现,随着pH值的升高,TP5与阳离子交换剂配基间的静电引力减弱,吸附容量下降,扩散系数下降。在离子交换色谱的应用中根据该性质可以利用升高pH值的方法对多肽进行洗脱。同时,对TP5与NH-1树脂动态吸附行为的研究也进一步验证了其静态吸附热力学的理论,其吸附反应为放热反应,升高温度对于吸附反应的进行无促进作用。通过间歇动力学实验,采用两相阻力模型和平行扩散模型拟合不同条件下NH1吸附TP5的速率曲线求得扩散系数,分析了TP5在阳离子交换剂NH1中的扩散行为。结果表明,随着温度的升高和pH值的降低,小肽在阴离子交换剂中的扩散系数总体上呈增大趋势。同时,对TP5在NH-1树脂上的解吸性能进行了研究,通过实验选择了0.05N浓度的氨水作为洗脱剂。所得洗脱率为100%,TP5纯度大于95%。本研究还详细分析了胸腺五肽与离子交换剂之间的相互作用,对于深入了解肽类分子离子交换平衡和动力学机理,以及离子交换色谱技术的应用具有一定的理论意义和实用价值。更多还原

【Abstract】 Kinetics and equilibrium of ion-exchange adsorption system is vital in the design and optimization of bioseparation. However, the theory of ion-exchange adsorption chromatography is not complete. The study hereinafter did something about the ion-exchange adsorption theory on peptides.Thymopetin( TP5) is studies as the model peptide and cation ion-exchanger NH1 the adsorbent. Static experiments for sorption behavior of TP5 in different conditions are observed. It indicates that along with the increase of pH, the electrostatic force between TP5 and the cation-exchange adsorbent decreases and the adsorbing capacity is lower. This property should be used for wash down the absorbed peptides.The ion-exchange adsorption kinetics of TP5 to the cation exchanger NH1 were studied in batch stirred cell. Two diffusion models, that is, pore diffusion and parallel diffusion model, were discussed in our paper to analyze the mass transfer of TP5 in the pore of matrix. The diffusion coefficients were determined by fitting uptake curves of TP5 adsorption to NH1 in different conditions (e.g. temperature, pH). The result showed that all of diffusion models could fit uptake curves of TP5 well.When pH increases, the ion interaction between TP5 and the exchanger is weakened, the absorbing capacity and diffusion coefficient decreases. This feature is used for desorption of TP5 from the ion exchanger. At the same time, the studies on dynamic absorption of TP5 onto NH-1 resin verified the theory of static absorption thermodynamics. The absorption releases heat, which is not positive for the processing of absorption.At the same time, the desorption features of TP5 on NH1 resin is studied. The desorbing condition is optimized to 0.05 N of ammonia. The desorption rate is 100% and the purity of TP5 is above95%.Interaction between TP5 and ion exchanger are described in detail. The results reported in the thesis provided an insight into ion-exchange adsorption equilibria and kinetics of peptides.更多还原