Identification and Characterization of German Cockroach Allergen / 소아알레르기및호흡기학회지

ABSTRACT

PURPOSE: Cockroaches have been reported one of the major causes of allergic disease such as bronchial asthma and allergic rhinitis. About 10% of children and 20% of adult respiratory allergy patients have positive results of allergy skin tests to cockroach allergen. This finding suggests that cockroach is also important allergen in Korea. Among 4,000 species, German cockroach seems predominant species in the Korean peninsula. Identification and charactrerization of the major allergen is the first step in German cockroach allergen research. But, there have been controversies. It may depends upon different identifying methods. The aim of our study was to identify the major allergen in German cockroach using Westernblot. METHODS: Crude German cockroach allergen extracts with or without protease inhibitor cocktail mixture were prepared, and protein patterns of these two extracts were compared using SDS-PAGE and Coommssie stain. Sera from 32 atopic asthmatic patients with positive allergy skin test against cockroach allergen were used for IgE immunoblot. RESULTS: Coomassie stain after SDS-PAGE demonstrated some discordance between the differently prepared crude allergen extracts. In comparison with the allergen extract which abolished endogenous protease activity, the untreated extract revealed new 32, 55 and 78 kD protein bands and 41 kD protein band was disappeared. About 60% of sera with positive allergy skin test revealed IgE binding bands in Westernblot. Among them, 10, 21, 25, 36 and 52 kD protein band might seemed important German cockroach allergen. CONCLUSION: Finding above may suggest that endogenous protease could denature allergenic proteins in the process of crude cockroach allergen extract. The 10, 21, 25, 36, and 52 kD might be the important allergens in German cockroach.