Gupta M N, Kaul R, Guoqiang D, Dissing U, Mattiasson B
Department of Biotechnology, Lund University, Sweden.
J Mol Recognit. 1996 Sep-Dec;9(5-6):356-9. doi: 10.1002/(sici)1099-1352(199634/12)9:5/6<356::aid-jmr328>3.0.co;2-x.
Affinity precipitation is being studied as a technique to be introduced at an early stage of downstream processing for the selective isolation of proteins. The technique utilizes a heterobifunctional ligand, which, in addition to having affinity for the target protein(s), possesses another function for controlling precipitation. The latter component is comprised of a polymer which can be made reversibly soluble and insoluble by altering a specific parameter such as pH or temperature. Different polymers of natural and synthetic origin have been used for this purpose. The soluble form of the ligand is used for the affinity binding step and precipitation is induced for obtaining separation of the affinity complex. Some of the polymers used in this laboratory include chitosan, alginate, Eudragit S-100 (copolymer of methacrylic acid and methyl methacrylate) and polyethyleneimine. Chitosan and alginate served as natural ligands for wheat germ agglutinin and pectinase, respectively. The aromatic dye Cibacron Blue 3GA coupled to Eudragit S 100 and polyethyleneimine way used for the affinity precipitation of some model enzymes such as lactate dehydrogenase and alcohol dehydrogenase. As prior removal of cell debris, etc., is essential for affinity precipitation, the possibility of integration of the technique with extraction in aqueous two-phase systems was also demonstrated.
亲和沉淀作为一种在下游加工早期阶段用于选择性分离蛋白质的技术正在被研究。该技术利用一种异双功能配体，它除了对目标蛋白质具有亲和力外，还具有控制沉淀的另一种功能。后一种成分由一种聚合物组成，该聚合物可通过改变特定参数（如pH值或温度）而可逆地溶解和沉淀。天然和合成来源的不同聚合物已被用于此目的。配体的可溶形式用于亲和结合步骤，通过诱导沉淀来实现亲和复合物的分离。本实验室使用的一些聚合物包括壳聚糖、藻酸盐、聚丙烯酸树脂S-100（甲基丙烯酸和甲基丙烯酸甲酯的共聚物）和聚乙烯亚胺。壳聚糖和藻酸盐分别作为小麦胚芽凝集素和果胶酶的天然配体。与聚丙烯酸树脂S 100和聚乙烯亚胺偶联的芳香染料Cibacron Blue 3GA用于一些模型酶如乳酸脱氢酶和乙醇脱氢酶的亲和沉淀。由于在进行亲和沉淀之前去除细胞碎片等是必不可少的，因此还证明了该技术与双水相系统萃取相结合的可能性。
