Specific histamine release capacity of peptides selected from the modelized der P I protein, a major allergen of Dermatophagoides pteronyssinus

Three-dimensional structure and IgE-binding properties of mature fully active Der p 1, a clinically relevant major allergen

“…Considering the previously described epitopes [10][11][12] (Fig 3, D), we found that stretch 15-33 is well accessible but relatively extended, and could constitute a discontinuous epitope with part of 188-199. Stretch 34-47, which contains the catalytic cysteine, is a helix buried in the interior of the molecule.…”

Specific Activation of Platelets from Patients Allergic to <i>Dermatophagoides pteronyssinus</i> by Synthetic Peptides Derived from the Allergen <i>Der p</i> I

“…In contrast, as estimated by our platelet stimulation test, pa tients sensitive to Hymenoptera venom or to pollen anti gens (data not shown, with high IgE serum level, but with out specific anti -Derp I antibodies) fail to respond to Derp I peptides. Second, the higher the level of scrum anti-Derp I IgE the higher is the capacity of D. pt-sensitivc patients to respond to several Derp I-derived peptides [42], However, though with a variable intensity, all patients tested for platelet reactivity responded more frequently to peptides Al and A2 than to peptide A3.…”

“…Thus, though our study investigated a limited number of peptides and the peptide 52-71 could stimulate more frequently platelets from D. pi-sensitive patients, the results that we obtained by analyzing the po tential IgE-depcndent reactivity of Derp I synthetic pep tides seem to comfort the idea that the amino acid se quence 117-133 could contain IgE epitopes. It must be em phasized that this sequence corresponds to a region of high hydrophilicity and accessibility (table 1) and has been revealed to be located on the surface on a modelized Derp I molecule [42], Nonetheless, though al variable degree, the three pep tides tested could specifically induce the IgE-dcpendent activation of platelets from D. pt-sensitive patients, and we cannot consider one single peptide as an immunodomi nant as already mentioned [27,43], In fact, recent experi ments carried out with four synthetic peptides (52-71,117-133,176-187,188-199) in order to determine their capacity of inducing specific histamine released led to similar con clusions. However, the histamine release pattern from ba sophils was different from that observed for the platelet stimulation.…”

Cellular and Molecular Characterization of a Major Soybean Allergen

“…In our investigations with peanut allergen Ara h 1 and Ara h 2 [25, 26]and work derived from other allergen studies including cow's milk [27], codfish [28], hazel [29]and shrimp [30], all have been shown to contain multiple IgE–binding epitopes. It is noteworthy that peptides from Der p 1 that released histamine from peripheral blood [22]did not have any amino acid sequences in common with IgE–binding epitopes from soybean–sensitive individuals. A linear amino acid sequence comparison of soybean IgE–binding epitopes of P34/Gly m 1 protein with the respective homologous linear amino acid sequences identified for the Der p 1 thiol protease allergen showed a similar use of D, R, T, Y, C and G amino acids.…”