Pepsin Digestion of Mouse Antibody

[摘要] In 1960 Nisonoff et al. described a method of producing F(ab′)2 fragments from human and rabbit IgG antibodies (1). The immunoglobulins are mixed with pepsin (3% by weight) in 0.1 M acetate buffer, pH 4.5. The mixture is stirred for 18 hr at 37°C. The enzymatic action is terminated by raising the pH to 7.0 and by precipitating the globulins in 18% (w/v) sodium sulfate. This precipitate contains a relatively homogeneous preparation of 5S F(ab′)2 antibody fragments. Recently, Sinclair (2) reported that when this procedure is followed for mouse γ globulins, the pepsin-digested material is grossly contaminated with intact 7S antibodies. In order to obtain the 5S material it was necessary to subject the pepsin digest to sucrose density gradient ultracentrifugation for 40 hr at 40,000 rpm, at 4°C. We have also encountered difficulties in preparing mouse F(ab′)2 according to the method described by Nisonoff et al.

[学科分类] 生物科学（综合）