Fab-fragment

Figure 1S.6 Enzymatic cleavage of immunoglobulin IgG. The enzyme papain splits the molecule in the hinge region, yielding two Fab fragments and one Fc fragment.

Figure 15.10 Schematic diagrams of the packing of the four-stranded p sheets of the constant domains Chi and Cl in an Fab fragment of IgG. The sheets are viewed perpendicular to the p strands in (a) and end-on in (b), where the four-stranded p sheets are blue.

Figure 15.13 (a) Drawing of a space-filiing model of the hypervariable regions of an Fab fragment. The superpositions of five sections are shown, cut through a model as shown in (b). It is clearly seen that all six hypervariable regions (L1-L3, H1-H3) contribute to the surface shown here. (From C. Chothia and A. Lesk, /. Mol. Biol. 196 901-917, 1987.)... 

Figure 15.15 Space-filling representation of a complex between lysozyme (green) and the Fab fragment of a monoclonal antilysozyme (blue and yellow). The Fab fragment and the antigen (lysozyme) have been separated in this diagram, and their combining surfaces are viewed end-on. Atoms that ate in contact in the complex are colored red both in Fab and lysozyme, except Gin 121 in lysozyme, which is violet. The diagram illustrates the large size of the interaction surfaces. (After A.G. Amit et al.. Science 233 747-753, 1986 courtesy of R. Poljak.)...

Wang, J., et al. Atomic structure of an ap T-cell receptor (TCR) heterodimer in complex with an anti-TCR Fab fragment derived from a mitogenic antibody. EMBO J. 17 10-26, 1988. 

Ranibizumab Anti-FAB fragment of VEGF Macular degeneration... 

CN immunoglobulin G (human-mouse monoclonal c7E3 clone p7E3VHhCy4 Fab fragment antihuman... 

Modulation of Phencyclidine (PCP) Pharmacokinetics With PCP-Specific Fab Fragments... 

Fab fragments (M.W. 50,000) have several advantages over IgG (M.W. 150,000) for use as the immunotherapeutic reagent (Smith et al. 1979). The Fab fragments distribute more rapidly and extensively than intact IgG. In addition, they are catabolized and excreted earlier than intact IgG. A final important advantage is that the Fab fragments are less antigenic than the intact IgG. 

The affinity constant of the Fab fragments we produced for these studies (discussed below) was approximately 3.0xl09 M"1. This means that the Fab fragments would have about 138 to 750 times greater affinity for PCP than for the receptor. 

C) was also used In the anti-PCP Fab fragment studies discussed below. The inset figure shoes a schematic representation of PCP in the dog as a two-... 

In addition to having a high affinity, the amount of antibody administered must be sufficient to reduce the body burden of PCP below that of toxic levels. Therefore, the effectiveness of a given dose of Fab fragments depends on its affinity and the amount of antibody administered relative to the dose of PCP. Since the affinity of the Fab fragments in the present study was so high... 

The affinity and cross-reactivity of the whole serum and Fab fragments were determined using equilibrium dialysis for the affinity determination and RIA for the cross-reactivity studies. The average intrinsic affinity constant (Ko) of the antibody (Nisonoff and Pressman 1958) changed very little throughout the... 

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