Molecular metamorphosis in polcalcin allergens by EF‐hand rearrangements and domain swapping

摘要: Polcalcins such as Bet v 4 and Phl p 7 are pollen allergens that constructed from EF-hand motifs, which very common well characterized helix-loop-helix motifs with calcium-binding functions, elementary building blocks. Being members of an exceptionally well-characterized protein superfamily, these highlight the fundamental challenge in explaining what features distinguish nonallergenic proteins. We found undergo oligomerization transitions characteristics markedly different those typically proteins: monomers to dimers distinct higher oligomers can be induced by increasing temperature; similarly, low concentrations destabilizing agents, e.g. SDS, induce 4. The changes quaternary structure, termed molecular metamorphosis, controlled a combination rearrangements domain swapping rather than classical law mass action. Using EF-hand-pairing model, we provide two-step model consistently explains substantiates observed metamorphosis. Moreover, unusual behavior suggests straightforward explanation how accomplish crosslinking IgE on mast cells, hallmark allergens.