Ligand Binding Preferences of Pathogenesis-Related Class 10 (PR-10) Allergens

Rationale: Many PR-10 proteins are allergens when inhaled or ingested.  One proposed function of these proteins is delivering bio-active compounds to wounds and/or the developing plant.  We examined ligand binding to seven known PR-10 allergens.  Ligand binding could well affect IgE binding.

 Methods: We generated pure, recombinant Ara h 8.01, Ara h 8.02, Cor a 1.02, Cor a 1.04, Que a 1.02, Que a 1.03 and Bet v 1.01 from peanut, hazelnut, white oak and birch respectively.  Twenty three putative ligands were tested for binding using a fluorescence assay.

 Results: All of the proteins bound apigenin, daidzein, genistein, quercetin and resveratrol.  Que a 1.03 bound the widest array of ligands including several fatty acids.  Preliminary structural studies show changes in protein structure with ligand binding.

Conclusions: Our results support the theory that these PR-10 allergens’ function in vivo is as a delivery vehicle for bio-active compounds.  Now that we have identified biologically-relevant ligands we will test the possibility that binding them to PR-10 proteins may influence allergenic potential.