skip to main content
Language:
Search Limited to: Search Limited to: Resource type Show Results with: Show Results with: Search type Index

Cockroach allergen Bla g 2: An unusual aspartic proteinase

Journal of Allergy and Clinical Immunology, 2005-07, Vol.116 (1), p.140-145 [Peer Reviewed Journal]

ISSN: 0091-6749 ;EISSN: 1365-2567 ;DOI: 10.1016/j.jaci.2005.04.024

Full text available

Citations Cited by
  • Title:
    Cockroach allergen Bla g 2: An unusual aspartic proteinase
  • Author: Wuenschmann, S ; Gustchina, A ; Chapman, MD ; Pomes, A
  • Is Part Of: Journal of Allergy and Clinical Immunology, 2005-07, Vol.116 (1), p.140-145
  • Description: Background Enzymatic activity of mite, fungal, and bee venom allergens is thought to potentiate their allergenicity. Bla g 2 is a potent cockroach allergen, but despite sharing sequence homology with aspartic proteinases, it contains critical amino acid substitutions that impair proteolytic activity. The biologic function of Bla g 2 remains unclear. Objective We sought to investigate the effects of specific amino acid substitutions on enzymatic activity, and the peptide-binding capability of Bla g 2. Methods Site-directed mutagenesis was used to produce a recombinant Bla g 2 mutant (Mut) with corrected canonical triads and a flap region. Another mutant (MutF super(-)) was expressed after additional mutations in the flap region of Mut. Bla g 2 wild-type (Wt), Mut, and MutF super(-) were assayed for aspartic proteinase activity, and Bla g 2 Wt was tested for pepstatin binding. Results Recombinant Bla g 2 Wt and Mut did not show enzymatic activity in a milk-clotting and hemoglobin assay. By using a modified hemoglobin assay, residual activity inhibited by pepstatin was detected for MutF super(-) and Wt at 20 mu g/mL, whereas pepsin was active at a 1000-fold lower concentration. Most of Bla g 2 binding to pepstatin-agarose was nonspecific. Conclusion Residual proteolytic activity was found for Bla g 2 at concentrations of approximately 4 mM. This weak activity suggests that proteolysis is not the primary function of this allergen and that it is unlikely to contribute to the allergenicity of Bla g 2. Bla g 2 has a cleft that might specifically bind ligands other than pepstatin.
  • Language: English
  • Identifier: ISSN: 0091-6749
    EISSN: 1365-2567
    DOI: 10.1016/j.jaci.2005.04.024
  • Source: IngentaConnect
    Geneva Foundation Free Medical Journals at publisher websites
    PubMed Central
Back to results list
INSPIRE LIBRARY - TON DUC THANG UNIVERSITY (84-028) 37 755 057 Feedback
19 Nguyen Huu Tho St. Dist.7, HCM thuvien@tdtu.edu.vn

Copyright © 2017 INSPIRE LIBRARY - TON DUC THANG UNIVERSITY

Searching Remote Databases, Please Wait