Each laboratory conducted proteomics studies on the Fab fragment
of NISTmAb (PDB: 5K8A) [1-3] and performed three HDX-MS runs.
Using phage display we have isolated CD44v6-binding fully human Fab fragments
that bind a defined peptide that overlaps with the epitopes of U36 and BIWA 1  (Figure 2).
Hahne et al., "Bacterial production and functional characterization of the Fab fragment
of the murine IgG1/[gamma] monoclonal antibody cmHsp70.1, a reagent for tumour diagnostics," Protein Engineering, Design and Selection, vol.
The crystal structure of the Fab fragment
and the octapeptide is shown in Figure 2.
All the MAbs reacted only with Fc, but not Fab fragments
of their immunogens (Figure 5).
Although site-specific bioconjugation was made possible through recombinant Fab fragment
production, the Fab fragments
were not labeled through the thiol groups in the current study because one chelate per Fab fragment
did not yield satisfactory signals.
Because the Fab fragment
accounts for only one-third of the IgG molecule, the coating of wells can be more efficient, and the site-specific biotinylation ensures that the fragments are in the correct orientation and able to bind antigen.
According to the manufacturer, Digibind is a polyclonal mixture of antibody Fab fragments
having a range of affinities, with dissociation constants (K.sub.d) ranging from [10.sup.-9] mol/L to [10.sup.-10] mol/L (1-0.1 nmol/L) (8).
Other clinical and emergency situations in which serum digoxin monitoring is recommended include: (a) in cases of digitalis intoxication, to determine the amount of antidote (Fab fragment
) needed; (b) in suspected poisoning by ingestion of plants such as oleandrin, to confirm the presence of digitalis-like poisons; (c) in patients with decreased renal function, to adjust digoxin dosage; and (d) in cases when other drugs known to interact with digoxin pharmacokinetics (e.g., quinidine, amiodorone, verapamil) are coadministered.
Such purification platforms can also be extended to purifying a diverse group of targets, including acidic IgMs, Fab fragments
, diabodies and bi-specific antibodies.
Treatment includes decontamination, close cardiac monitoring, supportive care and digoxin-specific Fab fragments
if it can be obtained.
Fc and Fab fragments
were produced from several purified human myeloma proteins of the IgG isotypes, by papain digestion (17).