[Purification of proteins in human plasma with new nylon affinity membranes]

A series of affinity membranes were prepared by using microporous nylon membrane as matrix and activation method with s-triazine and 1,4-butanediol diglycidyl ether, separately. Three proteins with clinic value, gamma-globulin, plasminogen and thrombin, were purified from human plasma by one step with affinity membrane chromatography. The purities of gamma-globulin purified were higher than 83%, and purification folds were higher than 5. The purity of gamma-globulin obtained was higher than that of standard human gamma-globulin. The efficiencies of gamma-globulin purification with affinity membranes prepared by two activation methods were equal. Plasminogen purified with affinity membranes prepared by s-triazine activation was higher than that by 1,4-butanediol diglycidyl ether activation. And SDS-PAGE analysis showed that the purities of gamma-globulin and plasminogen obtained were higher than that of the commercial product. In addition, the purification of thrombin from human plasma by one step with trypsin activation column and affinity membrane was studied. Thrombin with specific activity of 42 NIH unit/mg and 42.5 NIH unit/mg could be obtained from human plasma through affinity membranes prepared by s-triazine and 1,4-butanediol diglycidyl ether methods, respectively.