Structural characterization of the 60-kDa bermuda grass pollen isoallergens, a covalent flavoprotein.
Our studies suggest a tripartite structure for the 60-kDa allergen of Bermuda grass pollen (BG60) including a short N-terminal segment, a FAD-binding domain, and a C-terminal domain. The lower molecular weight isoallergens lack the N-terminal segment. The higher protease susceptibility and the lower melting temperature of approximately 20 degrees C of the lower molecular weight isoforms suggest that the N-terminal segment is essential for a compact structure. Database screening reveals that the protease-digested peptide sequences (approximately 180 residues in total) share 40% identity with the plant berberine bridge enzymes. In particular, a 24-residue peptide sequence displays high similarity to a conserved FAD-binding motif. The spectroscopic and SDS-PAGE analyses suggest that the cofactor FAD is covalently linked to the central domain. Therefore, we conclude that BG60 is identified as the first flavinylated allergen.
Liaw
S
S
Department of Life Science, National Yang-Ming University, Taipei, Taiwan.
Lee
D Y
DY
Chow
L P
LP
Lau
G X
GX
Su
S N
SN
Chow
L
L
D000485:Allergens / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D001665:Binding Sites; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D005420:Flavoproteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008670:Metals / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D006109:Poaceae / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011058:Pollen / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D017434:Protein Structure, Tertiary; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology; D017386:Sequence Homology, Amino Acid
D000485:Allergens; D005420:Flavoproteins; D008670:Metals; D010940:Plant Proteins; D005182:Flavin-Adenine Dinucleotide