Molecular and structural analysis of the panallergen profilin B cell epitopes defined by monoclonal antibodies.
Interactions of five mouse mAb (10A4, 5F2, 9A7, 9G4 and 3H8) and sunflower profilin were characterized using synthetic overlapping peptides. All the continuous B cell epitopes analyzed in this work were 6-10 amino acids in length, and clustered at the N- and C-terminal alpha-helices and a two-stranded segment composed of residues 40-50. Mutational analysis of the epitopes revealed that single amino acid changes within these peptides had dramatic effects on IgG-binding characteristics. A three-dimensional molecular model of sunflower profilin was generated by homology modeling based on the crystal structure of Arabidopsis thaliana profilin. All but one of the murine B cell epitopes defined in this work were located on the surface of the profilin molecule in the alpha-helices (10A4 and 3H8) or in the turns (5F2 and 9G4). In contrast, 9A7 epitope was located in the profilin core and partially buried by the C-terminal. Two mAb (5F2 and 10A4) inhibited the binding of anti-profilin human IgE up to 52%. In contrast, mAb 3H8 seemed to enhance the binding of anti-profilin IgE of sera from allergic patients.
Asturias
Juan A
JA
Research and Development Department, Bial-Arístegui, Alameda Urquijo 27, 48008 Bilbao, Spain. la.lp@bial.es
Gómez-Bayón
Nuria
N
Arilla
M Carmen
MC
Sánchez-Pulido
Luis
L
Valencia
Alfonso
A
Martínez
Alberto
A
D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D029681:Arabidopsis Proteins; D001402:B-Lymphocytes / Q000276:immunology*; D003285:Contractile Proteins; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D008840:Microfilament Proteins / Q000276:immunology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000276:immunology; D051304:Profilins; D016415:Sequence Alignment
D000485:Allergens; D000911:Antibodies, Monoclonal; D029681:Arabidopsis Proteins; D003285:Contractile Proteins; D018985:Epitopes, B-Lymphocyte; D007074:Immunoglobulin G; D008840:Microfilament Proteins; C495746:PRF1 protein, Arabidopsis; C495739:Pfn1 protein, mouse; D010940:Plant Proteins; D051304:Profilins; D007073:Immunoglobulin E