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THE IDENTIFICATION AND CHARACTERIZATION OF AN LGE-INDUCING PROTEIN IN METARHIZIUM ANISOPLIAE EXTRACT
Citation:
Ward, MDW, L B. Copeland, M J. Donohue, AND J A. Shoemaker. THE IDENTIFICATION AND CHARACTERIZATION OF AN LGE-INDUCING PROTEIN IN METARHIZIUM ANISOPLIAE EXTRACT. Presented at American Academy of Allergy, Asthma, and Immunology Annual Meeting, San Antonio, TX, March 18-22, 2005.
Description:
Molds are ubiquitous components of the indoor environment and have been associated with exacerbation of asthma as well as a number of other health effects. Their contribution to the induction of allergic asthma is less certain. Previously, we have shown that BALB/c mice exposed to an extract of the biopesticide Metarhizium anisopliae (MACA) have immune, inflammatory and respiratory physiological responses characteristic of allergic lung disease. Our objective was to identify and characterize mold extract components that induce an IgE response in the mouse model. Methods: M. anisopliae mycelium and conidia extracts, as well as, the inducible protease and chitinase filtrate were separated by SDS-PAGE. Hyperimmune serum against MACA was used as the primary antibody source in Western blot analysis. The mycelium proteins were further characterized by 2-dimensional (2-D) gel electrophoresis and mass spectrometric analysis (matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and electrospray ionization mass spectrometry (ESI-MS/MS)). Results: IgE-inducing proteins were identified in all three fungal component extracts/filtrate by Western blot analysis. 2-D gel immunoblots of the mycelium extract show 8 protein spots with acidic pIs ranging between pH 4.8 and pH 5.5. Following mass spectrometry analysis of these mycelium peptides/proteins, databases were searched for potential sequence or domain homology to known allergens using MASCOT (database-mining algorithm). M. anisopliae mycelium 2-D gel protein spots #1-5 have demonstrated sequence or antibody binding homology to the enzyme catalase. Conclusions: The identification of IgE binding proteins in the fungal extracts provides further evidence that M. anisopliae has the potential to induce allergy. Additionally, characterization of these proteins increases the data available to elucidate the features of IgE inducing proteins. (This abstract does not reflect EPA policy.)