Allergenic Characterization of a Novel Allergen, Homologous to Chymotrypsin, from German Cockroach

• Published in: Allergy, asthma & immunology research Vol. 7; no. 3; pp. 283 - 289
• Main Authors: Jeong, Kyoung Yong, Son, Mina, Lee, Jae-Hyun, Hong, Chein-Soo, Park, Jung-Won
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Academy of Asthma, Allergy and Clinical Immunology; The Korean Academy of Pediatric Allergy and Respiratory Disease 01.05.2015; 대한천식알레르기학회
• Subjects: Dermatophagoides pteronyssinus; Escherichia coli; Original; 내과학; Allergens; chymotrypsin; German cockroach
• ISSN: 2092-7355; 2092-7363
• DOI: 10.4168/aair.2015.7.3.283

Cockroach feces are known to be rich in IgE-reactive components. Various protease allergens were identified by proteomic analysis of German cockroach fecal extract in a previous study. In this study, we characterized a novel allergen, a chymotrypsin-like serine protease. A cDNA sequence homologous to chymotrypsin was obtained by analysis of German cockroach expressed sequence tag (EST) clones. The recombinant chymotrypsins from the German cockroach and house dust mite (Der f 6) were expressed in Escherichia coli using the pEXP5NT/TOPO vector system, and their allergenicity was investigated by ELISA. The deduced amino acid sequence of German cockroach chymotrypsin showed 32.7 to 43.1% identity with mite group 3 (trypsin) and group 6 (chymotrypsin) allergens. Sera from 8 of 28 German cockroach allergy subjects (28.6%) showed IgE binding to the recombinant protein. IgE binding to the recombinant cockroach chymotrypsin was inhibited by house dust mite chymotrypsin Der f 6, while it minimally inhibited the German cockroach whole body extract. A novel allergen homologous to chymotrypsin was identified from the German cockroach and was cross-reactive with Der f 6.