Isolation and purification of human haptoglobin by ion exchange chromatography / 军事医学

Objective To develop an effective process for isolating and purifying haptoglobin ( Hp) from Cohn fractionⅣby a new ion exchange chromatography and to preliminarily identify and analyze the product of each purification step . Methods The fraction was first diluted and impurities were adsorbed with Rivanol .Then, the supernatant was treated with 50%ammonium sulfate.Finally, the precipitate was redissolved , and Hp was purified further with Q Sepharose Fast Flow chromatography .Native-PAGE was used to measure the activity of the haptoglobin-bound hemoglobin , while SDS-PAGE analysis and immunoblot were used for identification of the target protein .Results After pretreatment , some of the impuri-ties were removed from the Cohn fraction Ⅳ, and the target protein was enriched .In our case, the target protein was Hp and Hp2-2 was the main phenotype in the human plasma fraction Ⅳ.Target protein band and high purity were identified by SDS-PAGE.Immunoblot analysis further proved that this method could successfully isolate the target protein Hp , and the activity of 2.8 U/ml was measured by Native-PAGE method.Conclusion Haptoglobin is successfully isolated from human Cohn fractionⅣwith this method.The purification process is simple and suitable for scale-up production with a good prospect.

Establishment and optimization ofα2-macroglobulin activity detection assay / 军事医学

Objective To establish an assay for detecting α2-macroglobulin activity in Cohn fraction Ⅳ.Methodsα2-M reacted with trypsin to form α2-M-trypsin complex.After the chromogenic substrate Na-benzoyl-DL-arginine 4-nitroanilide hydrochloride ( BAPNA) was added, absorption at 410 nm was detected with the microplate reader .α2-M activity in Cohn fractionⅣwas quantitatively detected according to the established standard curve of plasma α2-M activity. Result Several critical parameters in this assay were optimized .A standard curve of plasma α2-M activity was established . According to this standard curve ,α2-M activity in Cohn fraction Ⅳsample was detected to be 1.578 PU/ml.Conclusion Using normal human plasma as the reference material , theα2-M activity in Cohn fractionⅣcan be detected through chro-mogenic substrate assay.This study provides a simple method to detect α2-M activity during the purification process of α2-M from Cohn fraction Ⅳ.