There is scarce information about the biological function of many allergens in house dust and storage mites. In the last years, several studies have reported on the enzymatic activity of some mite allergens. To investigate the enzymatic activity in whole cultures and mite bodies of house dust and storage mites, chitinase, collagenase, cysteine protease and keratinase activity was determined in extracts of Dermatophagoides pteronyssinus (DP), D. farinae (DF), D. microceras (DM), Euroglyphus maynei (EM), Glycyphagus domesticus (GD), Blomia tropicalis (BT), Acarus siro (AS) and Chortoglyphus arcuatus (CA). All mite species were grown on a low allergenic substrate. Mite bodies were harvested using a modified escape-method. Whole cultures and mite bodies were extracted and stored at -20°C until further use. Protein content was determined according to method of Bradford. Enzymatic assays were performed following standardized procedures. Chitinase activity was detected in all extracts from whole culture and mite bodies. Chitinase activity was higher in storage than in house dust mites. The greatest activity was detected in the body extracts of storage mites. Cysteine protease activity was detected in all mite bodies; whole cultures showed little or no activity. Cysteine protease activity in mite bodies of DF, DM, and DP was much higher than in mite bodies of storage mites. Collagenase activity and keratinase-activity was detected only after prolonged incubation. Whole cultures had more collagenase activity than mite bodies. Cysteine protease and chitinase activity are clearly present in all extracts, but whole cultures have much less activity than mite bodies. Mite bodies from storage mites have higher chitinase activity than house dust mites. Whole cultures have more collagenase and keratinase activity than mite bodies.
