The specificity of the mAbs against Ara h 2 is high enough to distinguish Ara h2
from the other common food allergens in mixtures.
(*Statistically significant.) Sentitised Allergic ISAC Ara h1 50% * 7% ISAC Ara h2
83% * 7% ISAC Ara h3 38% * 3% Note: Table made from bar graph.
CRD testing showed that the IgE response to a particular peanut protein, called Ara H2
, may prove useful in separating children with true allergies from those with a peanut sensitivity.
With the objective of determining whether protein structure contributes to the ability of allergens to resist denaturation and digestions by enzymes encountered in the human gastrointestinal (GI) tract, a major peanut allergen, Ara h2, was studied.
Several methods have been used to gain a better understanding of the structural properties of Ara h2 that may contribute to its stability and allergenicity.
The Ara h2 protein was exposed to proteases encountered in the GI tract to determine whether the native protein structure, as mediated by disulfide bonds, played any role in protecting it from degradation.
To determine if the most protease-resistant Ara h2 fragments contained IgE-binding epitopes, the protein was exposed to chymotrypsin, and the reactions were electrophoresed on SDS-PAGE gels, blotted to nitrocellulose, and probed with serum IgE from a pool of peanut-sensitive patients.
There was some controversy among the participants regarding the use of only pure proteins or even pure epitopes, such as arachis hypogaea 2 (Ara h2) from peanut, as the sole positive versus the use of crude protein extracts.
(2001) both reported a threshold of 100 [micro]g total peanut protein or 6 [micro]g of the peanut allergen Ara h2, and a no-observable effect level (NOEL) of between 30 and 50 [micro]g peanut protein or 2-3 [micro]g of Ara h2 in patients with peanut allergy, using DBPCFCs.
Food Allergen Allergen serving Threshold ([micro]g) Peanut Ara h2 6% of total 100 peanut protein protein (a) or 6 Ara h2 (Wensing et al.
Using the purified three major peanut allergens, Ara h1, Ara h2
, and Ara h3, the IgG2a responses were determined in sera of rats sensitized orally or intraperitoneally with peanut proteins.