Papain digestion

Figure 20.11 Papain digestion of IgG antibodies primarily results in cleavage in the hinge region above the interchain disulfides. This produces two heavy-light chain pairs, called Fab fragments, each containing one antigen binding site. The Fc region normally can be recovered intact.

Fab fragment containing amine groups (from papain digestion of IgG)... 

Figure 4.5. Structure of myosin. Myosin comprises both light and heavy chains. The heavy chains may be cleaved by trypsin to generate light meromyosin (LMM) and heavy mero-myosin (HMM). Papain digestion of HMM yields subfragments SI and S2 each SI fragment contains an ATPase site and an actin-binding site. The light chains modify the activity of the ATPase.

Moorehouse K.G., Nashabeh W., Deveney J., Bjork N.S., Mulkerrin M.G., and Ryskamp T. (1997), Validation of an HPLC method for the analysis of the charge heterogeneity of the recombinant monoclonal antibody IDEC-C2B8 after papain digestion, J. Pharm. Biomed. Anal. 16, 593-603. 

Figure 7. Residual activities of papain-digested CBH I (open symbols) and CBH II (closed symbols). The enzymes ( 180 /jM) were incubated (pH 5.0, 25°C) with 0.6 fiM papain (300 1). Aliquots (50 /d) were removed at times indicated to measure the Avicelase activities (A, A) or to measure their activities against a small, chromophoric substrate as described in the text (CNPL in the case of CBH I, -o- MeUmbGs in the case of CBH II, - -). Residual activities are given as percent of the original.

After digestion with chondroitinase ABC, a dermatan sulfate proteoglycan from mouse cultured-cells,299 gave two polypeptides, and papain digestion... 

Fig. 2. Papain digestion of an antibody molecule yields two univalent Fab fragments and an Fc fragment whereas pepsin digestion yields a bivalent F(ab )2 fragment.

Binding kinetics were determined using surface plasmon resonance. Human integrin a,/3i was immobilized on the sensor chip. Kd was calculated from koS/k0 . Clones 11, 7, 4, 24, and 2 represent five humanized LM609 versions. Fab were produced by E. coli except for mouse which was prepared from IgG by papain digestion. 

Figure 32.3. The structure of the antibody molecule. All immunoglobulins consist of a basic subunit made up of four polypeptide chains (two light and two heavy) bound together by disulfide bonds. The variable region of the molecule contains the antigen binding site. Papain digestion yields a constant fragment (Fc) and variable fragments (Fab).

Fig. 2. Immunoelectrophoresis of undigested goat IgG (upper well), and of Fab and Fc from papain digestion of goat IgG (lower well), showing the electrophoretic difference and the reaction of nonidentity between the Fab and the Fc fragments. The slot contains antibody to goat IgG.

Fig. 3. Immunoelectrophoresis of separated Fab (upper three wells) and Fc (lower three wells), foHowing DEAE chromatography of a papain digest of goat IgG. The slots contain antibody to goat IgG.

SJ Boguslawski, et al. Improved procedure for preparation of F (ab )2 fragments of mouse IgGs by papain digestion. J Immunol Meth 120 51, 1989. 

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