2opo

From Proteopedia

Revision as of 11:07, 21 November 2007

Crystal structure of the calcium-binding pollen allergen Che a 3

Overview

BACKGROUND: Little is known about the molecular properties of chenopod, allergens. Recently, profilin and 2 EF-hand calcium-binding protein, (polcalcin) have been shown to play a role in chenopod pollinosis., OBJECTIVE: We sought to analyze these panallergens in chenopod pollen and, to evaluate their involvement in the allergy to this biologic source., METHODS: Profilin and polcalcin were purified to homogeneity and, characterized by using spectrometric and chemical methods. Immunologic, analyses were performed by means of immunoblotting, ELISA, and competitive, inhibition assays with olive profilin- and polcalcin-specific rabbit, polyclonal antibodies and sera from patients with chenopod allergy. cDNAs, encoding these proteins were cloned by means of PCR and sequenced., RESULTS: Purified Che a 2 (profilin) and Che a 3 (polcalcin) exhibited, prevalences of 55% and 46%, respectively, in patients (n=104), hypersensitive to chenopod pollen. Both purified allergens individually, inhibited the IgE binding to the whole pollen extract and showed strong, cross-reactivity with the corresponding olive pollen profilin (Ole e 2), and polcalcin (Ole e 3). Chenopod profilin consists of a 131-amino-acid, chain that displays identities of approximately 75% and 82% with pollen, and food profilins, respectively. Che a 3 (86 amino acids) displays, similarity (65% to 82% identity) with polcalcins from pollens of olive, birch, alder, rapeseed, and timothy. CONCLUSION: Profilin and polcalcin, are relevant panallergens in chenopod pollen and good candidates to be, involved in IgE cross-reactivity with other pollen sources, thus, explaining the highly frequent polysensitization of patients allergic to, chenopod.

About this Structure

2OPO is a Single protein structure of sequence from Chenopodium album with CA and SO4 as ligands. This structure superseeds the now removed PDB entry 1PMZ. Full crystallographic information is available from OCA.

Reference

Profilin (Che a 2) and polcalcin (Che a 3) are relevant allergens of Chenopodium album pollen: isolation, amino acid sequences, and immunologic properties., Barderas R, Villalba M, Pascual CY, Batanero E, Rodriguez R, J Allergy Clin Immunol. 2004 Jun;113(6):1192-8. PMID:15208604

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