Crystal structure of the dog lipocalin allergen Can f 2: implications for cross-reactivity to the cat allergen Fel d 4.
The dog lipocalin allergen Can f 2 is an important cause of allergic sensitization in humans worldwide. Here, the first crystal structure of recombinant rCan f 2 at 1.45 A resolution displays a classical lipocalin fold with a conserved Gly-Xaa-Trp motif, in which Trp19 stabilizes the overall topology of the monomeric rCan f 2. Phe38 and Tyr84 localized on the L1 and L5 loops, respectively, control access to the highly hydrophobic calyx. Although the rCan f 2 calyx is nearly identical with the aero-allergens MUP1, Equ c 1 and A2U from mouse, horse and rat, respectively, no IgE cross-reactivity was found using sera from five mono-sensitized subjects. However, clear IgE cross-reactivity was demonstrated between Can f 2 and the cat allergen Fel d 4, although they share less than 22% sequence identity. This suggests a role for these allergens in co-sensitization between cat- and dog-allergic patients.
Madhurantakam
Chaithanya
C
Centre for Infectious Medicine, F59, Department of Medicine Huddinge, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden.
Nilsson
Ola B
OB
Uchtenhagen
Hannes
H
Konradsen
Jon
J
Saarne
Tiiu
T
Högbom
Erik
E
Sandalova
Tatyana
T
Grönlund
Hans
H
Achour
Adnane
A
D000485:Allergens / Q000737:chemistry* / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D052179:Antigens, Plant; D002415:Cats; D003429:Cross Reactions; D003460:Crystallization; D018360:Crystallography, X-Ray; D004285:Dogs; D005260:Female; D006023:Glycoproteins / Q000737:chemistry* / Q000276:immunology*; D006801:Humans; D054834:Lipocalins / Q000737:chemistry* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
D000485:Allergens; D052179:Antigens, Plant; C499337:Fel d 4 allergen, Felis domesticus; D006023:Glycoproteins; D054834:Lipocalins; C110827:allergen Can f 2