Venâncio A, Teixeira J A, Mota M
Centro de Engenharia Química da Universidade do Porto, R. Bragas, Portugal.
Biotechnol Prog. 1993 Nov-Dec;9(6):635-9. doi: 10.1021/bp00024a010.
A new aqueous two-phase system based on crude hydroxypropyl starch (HPS) and poly(ethylene glycol) (PEG) is described. Unlike other polymer-polymer aqueous two-phase systems, the HPS used is commercially available. Previous works have characterized almost exclusively purified carbohydrates or their derivatives, having neglected the large amount of gums and carbohydrates already used in the paper, food, or textile industries. Two-phase aqueous polymer systems based on such commercial polymers may have as a drawback their degree of purity, which may affect the separation procedure. However, their lower cost should encourage studies on their use in aqueous two-phase polymer extraction. The influence of temperature, pH, and ionic strength on the partition of several different molecular weight and isoelectric point proteins and whole cells was studied. The results obtained were compared with corresponding dextran-PEG systems, Aquaphase PPT-PEG systems, crude dextran-PEG systems, maltodextrin-PEG systems, and Klucel L-pluronic systems. Protein partition coefficient results exhibited higher values than those in corresponding systems. It is shown that this system, based on a crude hydroxypropyl starch, is highly attractive as an initial purification step.
本文描述了一种基于粗羟丙基淀粉（HPS）和聚乙二醇（PEG）的新型水相双相系统。与其他聚合物-聚合物水相双相系统不同，所使用的HPS是市售的。以往的研究几乎只对纯化的碳水化合物或其衍生物进行了表征，而忽略了造纸、食品或纺织工业中已经使用的大量树胶和碳水化合物。基于此类商业聚合物的水相双相聚合物系统可能存在纯度问题，这可能会影响分离过程。然而，它们较低的成本应该会促使人们对其在水相双相聚合物萃取中的应用进行研究。研究了温度、pH值和离子强度对几种不同分子量和等电点的蛋白质及全细胞分配的影响。将所得结果与相应的葡聚糖-PEG系统、Aquaphase PPT-PEG系统、粗葡聚糖-PEG系统、麦芽糊精-PEG系统和Klucel L-普朗尼克系统进行了比较。蛋白质分配系数结果显示出比相应系统更高的值。结果表明，这种基于粗羟丙基淀粉的系统作为初步纯化步骤具有很高的吸引力。
