Molecular and immunological characterization of profilin from mugwort pollen.
In late summer in Europe, pollen of mugwort is one of the major sources of atopic allergens. No information about the complete molecular structure of any mugwort allergen has been published so far. Here we report the isolation and characterization of mugwort pollen cDNA clones coding for two isoforms of the panallergen profilin. Thirty-six percent of the mugwort-allergic patients tested displayed IgE antibodies against natural and recombinant profilin, and no significant differences were observed in the IgE-binding properties of the isoforms. One profilin isoform was purified to homogeneity and detailed structural analysis indicated that the protein exists in solution as dimers and tetramers stabilized by sulfydryl and/or ionic interactions. Profilin monomers were detectable only after exposure of multimers to harsh denaturing conditions. Dimers and tetramers did not significantly differ in their ability to bind serum IgE from mugwort pollen-allergic patients. However, oligomeric forms might have a higher allergenic potential than monomers because larger molecules would have additional epitopes for IgE-mediated histamine release. Profilin isolated from mugwort pollen also formed multimers. Thus, oligomerization is not an artifact resulting from the recombinant production of the allergen. Inhibition experiments showed extensive IgE cross-reactivity of recombinant mugwort profilin and profilin from various pollen and food extracts.
Wopfner
Nicole
N
Institute of Genetics, University of Salzburg, A-5020 Salzburg, Austria.
Willeroidee
Marika
M
Hebenstreit
Daniel
D
van Ree
Ronald
R
Aalbers
Marja
M
Briza
Peter
P
Thalhamer
Josef
J
Ebner
Christof
C
Richter
Klaus
K
Ferreira
Fatima
F
D000485:Allergens / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D019306:Artemisia / Q000737:chemistry*; D002850:Chromatography, Gel; D003285:Contractile Proteins; D018076:DNA, Complementary / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D007536:Isomerism; D008840:Microfilament Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D008969:Molecular Sequence Data; D011058:Pollen / Q000737:chemistry* / Q000276:immunology; D051304:Profilins; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011817:Rabbits / Q000276:immunology; D011852:Radioallergosorbent Test; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature
D000485:Allergens; D003285:Contractile Proteins; D018076:DNA, Complementary; D008840:Microfilament Proteins; D051304:Profilins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D007073:Immunoglobulin E