Molecular cloning, purification, and IgE-binding of a recombinant class I chitinase from Hevea brasiliensis leaves (rHev b 11.0102).
BACKGROUND
Class I chitinase in natural rubber latex (NRL) has been assumed to be an important allergen, especially concerning its cross-reactivity with fruits like avocado and banana.


OBJECTIVE
The present study aimed to produce a recombinant latex class I chitinase from Hevea brasiliensis leaves and to study its immunoglobulin (Ig)E-binding reactivity.


METHODS
A class I chitinase-specific complementary DNA from H. brasiliensis leaves was synthesized, subcloned, sequenced and overexpressed in fusion with the maltose-binding protein (MBP) in Escherichia coli. The IgE-binding reactivity of this protein was studied by the Pharmacia CAP System and by immunoblot experiments using sera from latex-allergic patients.


RESULTS
The rHev b 11.0102 was found to have a length of 295 amino acid residues and contains an N-terminal hevein-like domain with a 56% homology to hevein. Analysis by the CAP method revealed the presence of rHev b 11.0102-specific IgE antibodies in 17 of 58 sera (29%) of IgE-mediated latex-allergic subjects tested. Immunoblot analysis of the MBP-rHev b 11.0102 fusion protein and the MBP carrier protein as a negative control confirmed the IgE-reactivity of rHev b 11.0102.


CONCLUSIONS
Due to its IgE-reactivity rHev b 11.0102 represents an allergen of intermediate prevalence in NRL. Its property to cross-react with certain fruits makes it an important supplement in the diagnostic panel of recombinant NRL allergens.
Rihs
H-P
HP
Research Institute for Occupational Medicine of the Berufsgenossenschaften (BGFA), Institute of the Ruhr-University, Bochum, Germany.
Dumont
B
B
Rozynek
P
P
Lundberg
M
M
Cremer
R
R
Brüning
T
T
Raulf-Heimsoth
M
M
D000293:Adolescent; D000328:Adult; D000485:Allergens; D000595:Amino Acid Sequence; D001483:Base Sequence; D002648:Child; D002688:Chitinases / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D003001:Cloning, Molecular; D003429:Cross Reactions / Q000276:immunology; D005260:Female; D028482:Hevea / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D007109:Immunity; D007073:Immunoglobulin E / Q000276:immunology*; D007840:Latex / Q000737:chemistry* / Q000276:immunology; D020315:Latex Hypersensitivity / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D011994:Recombinant Proteins
D000485:Allergens; D007840:Latex; D010940:Plant Proteins; D011994:Recombinant Proteins; D007073:Immunoglobulin E; D002688:Chitinases