Enzymatic activity in body and fecal extracts of the storage mite Chortoglyphus arcuatus.
BACKGROUND
Chortoglyphus arcuatus has been described in many countries. Many allergens are potent enzymes, which may promote a Th2 immune response. The aim of this study was to evaluate the enzymatic activity of body and fecal extracts of C. arcuatus.


METHODS
Feces and bodies of full-grown C. arcuatus cultures were separated by sieving, extracted in PBS, dialyzed and lyophilized. The antigenic profile of both extracts was determined by SDS-PAGE. Immunoblot experiments were conducted using a pool of sera from allergic individuals residing in Galicia, a region of Spain, where this species is abundant. The enzymatic activity of the extracts was evaluated by the zymogram technique. Serine and cysteine protease activity was measured using in vitro methods. The API Zym system was used to determine the enzymatic properties of the extracts.


RESULTS
The antigenic profile showed that the body extract contained more and better defined bands than the fecal extract. Allergens were detected in both extracts in a molecular weight range between 14 and 100 kDa. Gelatinolytic gels confirmed that fecal extracts contain more hydrolytic enzymatic activity than body extracts. Serine protease activity in fecal extracts was higher than in body extracts (5.98 vs. 2.701 IU of trypsin/mg of freeze-dried material). No cysteine protease activity was detected.


CONCLUSIONS
C. arcuatus extracts contain several allergens and proteins with high enzymatic activity, especially in the feces. Some of these allergens may be enzymes. Fecal extracts have more enzymatic activity than body extracts.
Carnés
Jerónimo
J
Hospital Xeral de Calde, Allergology Service, Lugo, Spain. jcarnes@leti.com
Boquete
Manuel
M
Carballada
Francisco J
FJ
Iraola
Victor
V
Gallego
Maria Teresa
MT
Fernández-Caldas
Enrique
E
D000485:Allergens / Q000032:analysis / Q000737:chemistry; D000818:Animals; D003546:Cysteine Endopeptidases / Q000378:metabolism; D005243:Feces / Q000201:enzymology*; D006798:Housing; D006801:Humans; D015151:Immunoblotting; D008925:Mites / Q000201:enzymology* / Q000276:immunology; D008970:Molecular Weight; D012697:Serine Endopeptidases / Q000378:metabolism; D013030:Spain; D014020:Tissue Extracts / Q000378:metabolism
D000485:Allergens; D014020:Tissue Extracts; D012697:Serine Endopeptidases; D003546:Cysteine Endopeptidases