小鼠单克隆抗体IgM Fabμ片段的制备

本文介绍了小鼠单克隆抗体IgM小分子活性片段的制备方法。在37℃和4℃下用胰蛋白酶消化IgM 4和24小时,其小片段用碘代乙酰胺烷基化,用Sephacryl S-200柱层析纯化。SDS-聚丙烯酰胺凝胶电泳证实:在37℃用胰酶裂解IgM,小片段分子量近50000(Fab),但其免疫活性较低:在4℃胰酶裂解IgM,小片段分子量为80 000～110 000(Fabμ),免疫活性与原IgM基本一致。我们用Fab μ片段与辣根过氧化物酶连接,其结合物用于双抗体夹心酶联免疫吸附试验,取得了满意的结果。

Preparation of Fab μ Fragments from Mouse Monoclonal IgM Antibodies

This paper presents a method for preparation of small, active fragments from mouse monoclonal IgM antibodies. We have compared the influence of temperature on the splitting products at 37℃ and 4℃ with trypsin digestion. The small fragments were alkylated with i odoacetamide and purified by means of Sephacryl S-200 column. The fragments obtained at 37℃ had a molecular weight approximately 50000(Fab) as determined by PAGE; its immunoactivity was lower. But at 4℃, the molecular weights of the fragments ranged from 80000 to 110000 (Fab μ),and its immunoactivity was similar to the original IgM. The Fab μ fragments were labelled with horseradish peroxidase (HRP) and these conjugtes have been used in sandwich-ELISA with satisfactory results.