1H4B

SOLUTION STRUCTURE OF THE BIRCH POLLEN ALLERGEN BET V 4

1H4B の概要

• エントリーDOI: 10.2210/pdb1h4b/pdb
• 分子名称: POLCALCIN BET V 4, CALCIUM ION (2 entities in total)
• 機能のキーワード: allergen, birch pollen allergen, calcium-binding polcalcin, heteronuclear nmr
• 由来する生物種: BETULA VERRUCOSA (WHITE BIRCH)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 9410.52

構造登録者

Neudecker, P.,Nerkamp, J.,Eisenmann, A.,Lauber, T.,Lehmann, K.,Schweimer, K.,Roesch, P. (登録日: 2003-02-26, 公開日: 2004-02-26, 最終更新日: 2024-05-15)

主引用文献

Neudecker, P.,Nerkamp, J.,Eisenmann, A.,Nourse, A.,Lauber, T.,Schweimer, K.,Lehmann, K.,Schwarzinger, S.,Ferreira, F.,Roesch, P.
Solution Structure, Dynamics, and Hydrodynamics of the Calcium-Bound Cross-Reactive Birch Pollen Allergen Bet V 4 Reveal a Canonical Monomeric Two EF-Hand Assembly with a Regulatory Function
J.Mol.Biol., 336:1141-, 2004

PubMed Abstract: Birch pollinosis is one of the prevailing allergic diseases. In all, 5-20% of birch pollinotics mount IgE antibodies against the minor birch pollen allergen Bet v 4, a Ca2+-binding polcalcin. Due to IgE cross-reactivity among the polcalcins these patients are polysensitized to various plant pollens. Determination of the high-resolution structure of holo Bet v 4 by heteronuclear NMR spectroscopy reveals a canonical two EF-hand assembly in the open conformation with interhelical angles closely resembling holo calmodulin. The polcalcin-specific amphipathic COOH-terminal alpha-helix covers only a part of the hydrophobic groove on the molecular surface. Unlike the polcalcin Phl p 7 from timothy grass, which was recently shown to form a domain-swapped dimer, the hydrodynamic parameters from NMR relaxation, NMR translational diffusion, and analytical ultracentrifugation indicate that both apo and holo Bet v 4 are predominantly monomeric, raising the question of the physiological and immunological significance of the dimeric form of these polcalcins, whose physiological function is still unknown. The reduced helicity and heat stability in the CD spectra, the poor chemical shift dispersion of the NMR spectra, and the slightly increased hydrodynamic radius of apo Bet v 4 indicate a reversible structural transition upon Ca2+ binding, which explains the reduced IgE binding capacity of apo Bet v 4. The remarkable structural similarity of holo Bet v 4 and holo Phl p 7 in spite of different oligomerization states explains the IgE cross-reactivity and indicates that canonical monomers and domain-swapped dimers may be of similar allergenicity. Together with the close structural homology to calmodulin and the hydrophobic ligand binding groove this transition suggests a regulatory function for Bet v 4.

PubMed: 15037075
DOI: 10.1016/J.JMB.2003.12.070

実験手法

SOLUTION NMR