Affiliations 

  • 1 Department of Biological Sciences, Sunway University, Bandar Sunway 47500, Selangor, Malaysia
  • 2 Allergy and Molecular Immunology Laboratory, Department of Biological Science, National University of Singapore, Singapore, 117543, Singapore
  • 3 Allergy and Molecular Immunology Laboratory, Department of Biological Science, National University of Singapore, Singapore, 117543, Singapore. dbscft@nus.edu.sg
Sci Rep, 2019 08 22;9(1):12239.
PMID: 31439916 DOI: 10.1038/s41598-019-48688-y

Abstract

Blomia tropicalis has been recognized as a cause of allergic diseases in the tropical and subtropical regions. Here we report the immuno-characterization of its group 2 allergen, Blo t 2. Allergen Blo t 2 was amplified from the cDNA of B. tropicalis using degenerate primers, expressed in Escherichia coli as a recombinant protein and purified to homogeneity. The mature protein of Blo t 2 was 126 amino acids long with 52% sequence identity to Der p 2 and apparent molecular mass of 15 kDa. Circular dichroism spectroscopy showed that Blo t 2 is mainly a beta-sheeted protein. We confirmed the presence of three disulfide bonds in recombinant (r) Blo t 2 protein using electrospray mass spectrometry. Thirty-four percent of dust-mite allergic individuals from the Singapore showed specific IgE binding to rBlo t 2 as tested using immuno dot-blots. IgE-cross reactivity assays showed that Blo t 2 had between 20-50% of unique IgE-epitopes compared to Der p 2. IgE binding of native and recombinant forms of Blo t 2 were highly concordant (r2 = 0.77, p 

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.