Crystallization and identification of the glycosylated moieties of two isoforms of the main allergen Hev b 2 and preliminary X-ray analysis of two polymorphs of isoform II.
Acta Crystallogr Sect F Struct Biol Cryst Commun
; 63(Pt 9): 787-91, 2007 Sep 01.
Article
en En
| MEDLINE
| ID: mdl-17768356
Latex from Hevea brasiliensis contains several allergenic proteins that are involved in type I allergy. One of them is Hev b 2, which is a beta-1,3-glucanase enzyme that exists in different isoforms with variable glycosylation content. Two glucanase isoforms were isolated from trees of the GV-42 clone by gel filtration, affinity and ion-exchange chromatography. Isoform I had a carbohydrate content of about 20%, with N-linked N-acetyl-glucosamine, N-acetyl-galactosamine, fucose and galactose residues as the main sugars, while isoform II showed 6% carbohydrate content consisting of N-acetyl-glucosamine, fucose, mannose and xylose. Both isoforms were crystallized by the hanging-drop vapour-diffusion method. Isoform I crystals were grown using 0.2 M trisodium citrate dihydrate, 0.1 M Na HEPES pH 7.5 and 20%(v/v) 2-propanol, but these crystals were not appropriate for data collection. Isoform II crystals were obtained under two conditions and X-ray diffraction data were collected from both. In the first condition (0.2 M trisodium citrate, 0.1 M sodium cacodylate pH 6.5, 30% 2-propanol), crystals belonging to the tetragonal space group P4(1) with unit-cell parameters a = b = 150.17, c = 77.41 A were obtained. In the second condition [0.2 M ammonium acetate, 0.1 M trisodium citrate dihydrate pH 5.6, 30%(w/v) polyethylene glycol 4000] the isoform II crystals belonged to the monoclinic space group P2(1), with unit-cell parameters a = 85.08, b = 89.67, c = 101.80 A, beta = 113.6 degrees. Preliminary analysis suggests that there are four molecules of isoform II in both asymmetric units.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Alérgenos
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Revista:
Acta Crystallogr Sect F Struct Biol Cryst Commun
Año:
2007
Tipo del documento:
Article
País de afiliación:
México
Pais de publicación:
Reino Unido