Extraordinary stability of IgE-binding Parietaria pollen allergens in relation to chemically bound flavonoids
| Autor: | M L Gonzalez Romano, L. Berrens, M.T. Gallego |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Protein Denaturation
Parietaria Flavonols Immunology Flavonoid Peptide medicine.disease_cause Epitope Pollen Botany otorhinolaryngologic diseases medicine Humans Molecular Biology Flavonoids chemistry.chemical_classification biology Isoelectric focusing Hydrolysis food and beverages Allergens Immunoglobulin E biology.organism_classification Peptide Fragments Enzyme chemistry Biochemistry Polyphenol Spectrophotometry Ultraviolet Isoelectric Focusing |
| Zdroj: | Molecular Immunology. 33:1287-1293 |
| ISSN: | 0161-5890 |
| DOI: | 10.1016/s0161-5890(96)00106-x |
| Popis: | It is known that the skin-active and IgE-binding components in Parietaria pollen extracts are not restricted to the predominant protein allergens of Mr 12 000–15 000, but are present as well among the naturally occurring constituents of Mr < 10 000. Indeed, the IgE-binding Parietaria pollen components are quite heterogeneous, ranging from high- to low-molecular mass, whereby the IgE-binding epitopes display an unusual chemical stability. Furthermore, the pollen of Parietaria species demonstrably contain a high proportion of flavonoid pigments. Since these pollen grains cannot be collected entirely free from non-pollen plant parts, the usual allergenic extracts of Parietaria encompass both the polyphenolic substrate molecules and the enzyme polyphenoloxidase as ingredients for the oxidative generation of flavonol-protein conjugates during the extraction process. In the present work this is illustrated by spectroscopic analyses of the free and bound flavonoids in Parietaria pollen extracts, as well as of the peptide fragments produced from the allergenic proteins by enzymatic or chemical hydrolysis. None of these relatively harsh treatments had a significant effect on the IgE-binding properties of the allergenic (sub-)components, even though detectable proteins in isoelectric focusing and immunoblotting were lost. It is proposed that the extraordinary stability of IgE-binding Parietaria components over a wide molecular range may be attributed to chromophoric flavonoid side-chains as (parts of) the corresponding B-cell epitopes. |
| Databáze: | OpenAIRE |
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