Monoclonal antibodies to the major feline allergen Fel d I. II. Single step affinity purification of Fel d I, N-terminal sequence analysis, and development of a sensitive two-site immunoassay to assess Fel d I exposure.

摘要: Two mAb were used to develop new techniques for the purification and quantitation of major feline salivary allergen, Felis domesticus allergen I (Fel d I). The was purified from aqueous house dust extract with a high Fel content by affinity chromatography over monoclonal immunosorbent elution 4 mM HCl, pH 2.5. This single step procedure gave 40 50% recovery 90% pure which, following final size exclusion HPLC, showed line on immunodiffusion crossed immunoelectrophoresis against monospecific anti-Fel polyclonal anti-cat dander antibodies. m.w. native 39,000 17,000 under nonreducing conditions gel electrophoresis. N-terminal amino acid sequence (33 residues) no homology other known protein sequences. combination SDS-PAGE data suggests that is non-covalently linked homodimer. A two-site RIA developed using directed different epitopes I. assay species-specific, highly sensitive (0.0004 U/ml), an excellent correlation inhibition (n = 27, r 0.93, p less than 0.001). Cat extracts immediate skin tests marked differences in (from 0.1 30 U/ml). Consistently levels found at monthly intervals six samples four houses cats (10 100 U/g dust). Comparisons mite pollen can contain greater micrograms/g either these allergens potent source foreign environmental antigens. Monoclonal provides breakthrough I, material would otherwise have been considered impossible (house both more easily standardized existing techniques. These will allow full structural antigenic analysis detailed studies relationship between cat antigen exposure development asthma.