title: Mass spectrometric investigation of molecular variability of grass pollen group 1 allergens.
abstract: Natural grass pollen allergens exhibit a wide variety of isoforms. Precise characterization of such microheterogeneity is essential to improve diagnosis and design appropriate immunotherapies. Moreover, standardization of allergen vaccine production is a prerequisite for product safety and efficiency. Both qualitative and quantitative analytical methods are thus required to monitor and control the huge natural variability of pollens, as well as final product quality. A proteomic approach has been set up to investigate in depth the structural variability of five group 1 allergens originating from distinct grass species (Ant o 1, Dac g 1, Lol p 1, Phl p 1, and Poa p 1). Whereas group 1 is the most conserved grass pollen allergen, great variations were shown between the various isoforms found in these five species using mass spectrometry, with many amino acid exchanges, as well as variations in proline hydroxylation level and in main N-glycan motifs. The presence of O-linked pentose residues was also demonstrated, with up to three consecutive units on the first hydroxyproline of Ant o 1. In addition, species-specific peptides were identified that might be used for product authentication or individual allergen quantification. Lastly, natural or process-induced modifications (deamidation, oxidation, glycation) were evidenced, which might constitute useful indicators of product degradation.
authors: CEA, iBitec-S Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France. francois.fenaille@cea.fr
authors: François
authors: F
authors: Fenaille
authors: Emmanuel
authors: E
authors: Nony
authors: Henri
authors: H
authors: Chabre
authors: Aurélie
authors: A
authors: Lautrette
authors: Marie-Noëlle
authors: MN
authors: Couret
authors: Thierry
authors: T
authors: Batard
authors: Philippe
authors: P
authors: Moingeon
authors: Eric
authors: E
authors: Ezan
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D006031:Glycosylation; D006900:Hydroxylation; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D010446:Peptide Fragments; D010449:Peptide Mapping / Q000379:methods; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D006109:Poaceae / Q000737:chemistry* / Q000378:metabolism; D011058:Pollen / Q000737:chemistry* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D013045:Species Specificity
chemical_list: D000485:Allergens; D010446:Peptide Fragments; D010940:Plant Proteins