To use paper cellulose as a carrier, immobilization of papain on paper cellulose was studied. Thus, papain was immobilized onto glutaraldehyde-activated paper cellulose under acid conditions. The enzymatic properties, such as proteolytic activity, heat-stability, glutaraldehyde volume fraction, enzyme amount and pH-activity profile, of the immobilized papain preparation were examined. The immobilization conditions were optimized by orthogonal experiments. The prepared products were applied to digest anti-HCG to obtain F(ab )2 fragments. The results indicated that the immobilized enzyme has an high activity at 40 ℃ when the pH of the buffer solution is 5. 0 as well as with the glutaraldehyde volume fraction is 0. 01%. Besides the enzyme concentration is 46 mg/g. The activity of the products can reach up to 19 250 U/g which are ten times higher than those came from the processes not optimized. The preparation and characterization of the F(ab')2 fragments of anti-HCG are presented in detail. The monoclonal antibody was digested with immobilized papain to produce antibody fragment. The F(ab')2 fragments were then purified by using DEAE-FF size exclusion chromatography. The F(ab')2 fragment(110 KDa) maintained potent suppressive activity and the titer can reaches 1:12 000.%利用纸纤维为载体,制备高活性的固定化木瓜蛋白酶并应用于抗HCG抗体的水解.利用戊二醛交联法,制备固定化木瓜蛋白酶,并通过一系列优化,得到最佳固定化条件,包括pH、给酶量、温度、戊二醛体积分数,将制备的固定化木瓜蛋白酶应用于抗HCG抗体水解并制备F(ab')2片段.研究表明:反应温度为40℃时,固定化酶在pH5.0,0.01 mol/L的醋酸缓冲液条件下,给酶量为46 mg/g载体,戊二醛体积分数为0.01％时,固定化酶的酶活达到最高19 250 U/g,相对于优化前1 940 U/g提高了近10倍,成功应用于抗HCG抗体水解制备F(ab')2片段:经SDS-PAGE电泳检测,F(ab’)2片段达到电泳纯.ELISA反应检测表明:片段仍保留较高的活性,效价为1:12 000.
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