The Fab fragment of the anti-polymorphic epithelial mucin antibody C595 (IgG3, κ) has been produced by digestion with papain. The purified antibody fragment retained its binding activity for the mucin in an indirect radioisotopic antiglobulin assay. The binding constant of the Fab fragment for the synthetic peptide (PDTRPAPGSTAPPAHGVTSA) corresponding to the 20-amino acid tandem repeat sequence found in the mucin protein core was determined to be 0.3 × 106 M-1 by measuring the capacity of the peptide to quench the fluorescence of the Fab fragment.
- fluorescence quenching
- mucin core related peptide
- polymorphic epithelial mucins