Watermelon profilin: characterization of a major allergen as a model for plant-derived food profilins.
BACKGROUND
Plant profilins have been reported as minor allergens. They are a well-known pan-allergen family responsible for cross-reactivity between plant-derived foods and pollens. Watermelon profilin has been reported to be a major allergen in watermelon (Citrullus lanatus).The aim of this study was to characterize recombinant watermelon profilin, confirming its reactivity for diagnostic purposes and the development of immunotherapy.


METHODS
Native profilin was purified from watermelon extract by affinity chromatography using poly-L-proline. Recombinant His-tagged profilin was produced in Pichia pastoris yeast using pPICZαA vector and purified by metal chelate affinity chromatography. ELISA and immunoblot were carried out with sera from 17 watermelon-allergic patients. Biological activity was tested by the basophil activation test.


RESULTS
Native profilin and recombinant profilin were purified and identified by mass spectrometry. Both show similar IgE reactivity in vitro and are biologically active.


CONCLUSIONS
Similarities were found in the IgE-binding patterns and biological activity of recombinant profilin and native profilin. Recombinant profilin may be a powerful tool for specific diagnosis.
Cases
Bárbara
B
Department of Immunology, Fundación Jiménez Díaz, Madrid, Spain.
Pastor-Vargas
Carlos
C
Dones
Félix Gil
FG
Perez-Gordo
Marina
M
Maroto
Aroa S
AS
de las Heras
Manuel
M
Vivanco
Fernando
F
Cuesta-Herranz
Javier
J
D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D002648:Child; D002675:Child, Preschool; D029773:Citrullus / Q000737:chemistry / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D008297:Male; D013058:Mass Spectrometry; D008954:Models, Biological; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics; D051304:Profilins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology*; D016415:Sequence Alignment
D051304:Profilins; D011994:Recombinant Proteins; D007073:Immunoglobulin E