Peptidomics of an in vitro digested α-Gal carrying protein revealed IgE-reactive peptides.
Sci Rep
; 7(1): 5201, 2017 07 12.
Article
em En
| MEDLINE
| ID: mdl-28701697
ABSTRACT
The mammalian carbohydrate galactose-α1,3-galactose (α-Gal) causes a novel form of food allergy, red meat allergy, where patients experience severe allergic reactions several hours after red meat consumption. Here we explored gastric digestion of α-Gal glycoproteins using an in vitro model. Bovine thyroglobulin (BTG), a typical α-Gal carrying glycoprotein, was digested with pepsin. The resulting peptides were characterised by SDS PAGE, immunoblot and ImmunoCAP using sera from 20 red meat allergic patients. During pepsinolysis of BTG, a wide range of peptide bands was observed of which 14 to 17 kDa peptides remained stable throughout the gastric phase. The presence of the α-Gal epitope on the obtained peptides was demonstrated by an anti-α-Gal antibody and IgE from red meat allergic patients. The α-Gal digests were able to inhibit up to 86% of IgE reactivity to BTG. Importantly, basophil activation test demonstrated that the allergenic activity of BTG was retained after digestion in all four tested patients. Mass spectrometry-based peptidomics revealed that these peptides represent mostly internal and C-terminal parts of the protein, where the most potent IgE-binding α-Gal residues were identified at Asn1756, Asn1850 and Asn2231. Thus allergenic α-Gal epitopes are stable to pepsinolysis, reinforcing their role as clinically relevant food allergens.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
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Tireoglobulina
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Imunoglobulina E
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Alérgenos
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Carne Vermelha
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Hipersensibilidade Alimentar
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Galactose
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2017
Tipo de documento:
Article