X-ray and NMR structure of Bet v 1, the origin of birch pollen allergy

Abstract

The three-dimensional structure of the major birch pollen allergen, the 17,500 M(r) acidic protein Bet v 1 (from the birch, Betula verrucosa), is presented as determined both in the crystalline state by X-ray diffraction and in solution by nuclear magnetic resonance (NMR) spectroscopy. This is the first experimentally determined structure of a clinically important inhalant major allergen, estimated to cause allergy in 5-10 million individuals worldwide. The structure shows three regions on the molecular surface predicted to harbour cross-reactive B-cell epitopes which provide a structural basis for the allergic symptoms that birch pollen allergic patients show when they encounter pollens from related trees such as hazel, alder and hornbeam. The structure also shows an unusual feature, a 30 A-long forked cavity that penetrates the entire protein.

Mutational epitope analysis of Pru av 1 and Api g 1, the major allergens of cherry (Prunus avium) and celery (Apium graveolens): correlating IgE reactivity with three-dimensional structure

“…Previously, we showed that the tertiary structure of Pru av 1 (formerly Pru a 1) [3] from cherry (Prunus avium) in solution, determined by heteronuclear multidimensional NMR spectroscopy, is virtually identical with that of the major birch (Betula verrucosa) allergen Bet v 1 [4,5]. The main feature of the 3D (three-dimensional) structure is a folded seven-stranded antiparallel β-sheet and two short α-helices that wrap around a long C-terminal α-helix to form a basket-like structure with a large hydrophobic cavity.…”

“…NMR spectroscopy, together with molecular modelling, fluorescence spectroscopy, X-ray crystallography and MS, provided strong evidence that the cavity of both Pru av 1 and Bet v 1 interacts with steroids and other lipids [7][8][9], but their exact physiological function remains unclear. The P-loop is one of three highly conserved regions on the surface of the Bet v 1 molecule proposed as IgE epitopes leading to cross-reactivity with pollen allergens of other trees of the Fagales order [5]. In the crystal structure of Bet v 1 in complex with a Fab fragment of the monoclonal murine IgG1 BV16, which was raised against Bet v 1 and partially inhibits binding of human IgE, the P-loop region constitutes the contact surface, with the side chain of Glu 45 located in a positively charged binding pocket forming two hydrogen bonds with the CDR3 (complementary determining region 3) of the heavy-chain variable domain [10].…”

The RNA Hydrolysis and the Cytokinin Binding Activities of PR-10 Proteins Are Differently Performed by Two Isoforms of the Pru p 1 Peach Major Allergen and Are Possibly Functionally Related

“…This is revealed by the structures of a number of PR-10 proteins obtained by NMR and x-ray crystallography, such as Bet v 1 from birch (Betula spp. ; Gajhede et al, 1996;Markovic-Housley et al, 2003), four isoforms of LlPR10 from yellow lupin (Lupinus luteus; Biesiadka et al, 2002;Pasternak et al, 2005;Fernandes et al, 2008), VrCSBP (cytokininspecific binding protein) from mung bean (Vigna radiata; Pasternak et al, 2006), Pru av 1 from cherry (Prunus avium; Neudecker et al, 2001), and Ap g 1 from celery (Apium graveolens; Schirmer et al, 2005).…”

T Cell Epitope-Containing Hypoallergenic Recombinant Fragments of the Major Birch Pollen Allergen, Bet v 1, Induce Blocking Antibodies

“…When analyzed by circular dichroism spectroscopy, the bacterially expressed rBet v 1 wild-type molecule was folded and consisted of mixed ␣ helical and ␤-sheet conformation (25,26). The three-dimensional structure of rBet v 1 was determined by x-ray crystallography and nuclear magnetic resonance analysis (27).…”