Mala s 12 is a major allergen in patients with atopic eczema and has sequence similarities to the GMC oxidoreductase family.
BACKGROUND
Atopic eczema (AE) is a chronic inflammatory skin disorder, characterized by impaired skin barrier and itch. The yeast Malassezia belongs to the normal human skin microflora and can induce IgE- and T-cell-mediated allergic reactions in AE patients. Previously, we have identified several IgE-binding components in Malassezia sympodialis extract.


METHODS
Here, we report cloning, production and characterization of a M. sympodialis 67-kDa allergen.


RESULTS
The sequence of the 67-kDa protein, termed Mala s 12, showed sequence similarity to the glucose-methanol-choline (GMC) oxidoreductase enzyme superfamily and was expressed as a recombinant protein in Escherichia coli. The purified protein bound flavin adenine dinucleotide with 1:1 stoichiometry per monomer of protein. The protein-bound flavin showed an extinction coefficient at 451 nm of 11.3 mM(-1)cm(-1). The recombinant 67-kDa protein did not show any enzymatic activity when tested as oxidase or dehydrogenase using choline, glucose, myo-inositol, methanol, ethanol, 1-pentanol, benzyl alcohol, 2-phenylethanol, cholesterol or lauryl alcohol as possible substrates. Recombinant Mala s 12 was recognized by serum IgE from 13 of 21 (62%) M. sympodialis-sensitized AE patients indicating that the 67-kDa component is a major allergen.


CONCLUSIONS
The data show that Mala s 12 has sequence similarity to the GMC oxidoreductase family and is a major allergen in AE patients.
Zargari
A
A
Department of Medicine, Clinical Allergy Research Unit, Karolinska Institutet and University Hospital, Stockholm, Sweden.
Selander
C
C
Rasool
O
O
Ghanem
M
M
Gadda
G
G
Crameri
R
R
Scheynius
A
A
D000328:Adult; D000485:Allergens / Q000235:genetics* / Q000276:immunology*; D000595:Amino Acid Sequence; D000946:Antigens, Fungal / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D003876:Dermatitis, Atopic / Q000209:etiology*; D005260:Female; D005948:Glucose Dehydrogenases / Q000235:genetics; D006801:Humans; D015151:Immunoblotting; D008290:Malassezia; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D000485:Allergens; D000946:Antigens, Fungal; D005948:Glucose Dehydrogenases