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. Thirtysix percent of the mugwort
allergic patients tested displayed IgE antibodies
against natural and recombinant profilin, and no significant differences were observed in the IgEbinding
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 pollenallergic patients. However, oligomeric
forms might have a higher allergenic potential than
monomers because larger molecules would have additional epitopes for IgEmediated 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
crossreactivity of recombinant mugwort profilin and
profilin from various pollen and food extracts.
Biological Chemistry keeps you up-to-date with the latest advances in the molecular life sciences. The journal publishes Research Articles, Short Communications, Reviews and Minireviews. Areas include: general biochemistry/pathobiochemistry, structural biology, molecular and cellular biology, genetics and epigenetics, virology, molecular medicine, plant molecular biology/biochemistry and novel experimental methodologies.