Evidence for an alpha helical T cell epitope in the C-terminus of the main birch pollen allergen Bet V 1.
Secondary structure prediction of the main birch pollen allergen Bet v 1 was found to be in good agreement with the secondary structural elements found by analysing the Bet v 1 circular dichroism data. According to both experiment and prediction, 32% of 160 amino acids participate in alpha helices, 21% in beta sheets, 24% in turns, and 23% in other structural motifs. The peptide LRAVESYLLAHS which represents one of the major T cell epitopes on Bet v 1 was shown to have a high propensity to form an alpha helix. Time-resolved fluorescence anisotropy measurements of the allergen revealed an overall rotational correlation time of 7.35 ns, which corresponds to a hydrodynamic molecular radius of 19.2 A. This refers to a monomeric Bet v 1 molecule in solution, which is also reflected in the narrow band width of the 1H-NMR spectrum. The results presented here are in good agreement with the recently solved NMR structure of Amb t 5: both allergens are monomers in solution with an extended C-terminal alpha helix containing a major T cell epitope.
Kungl
A J
AJ
Department of Immunodermatology, Sandoz Research Institute, Vienna, Austria.
Susani
M
M
Lindemann
A
A
Machius
M
M
Visser
A J
AJ
Scheiner
O
O
Kraft
D
D
Breitenbach
M
M
Auer
M
M
D000485:Allergens; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D002942:Circular Dichroism; D003001:Cloning, Molecular; D000939:Epitopes / Q000032:analysis* / Q000737:chemistry; D005454:Fluorescence Polarization; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014197:Trees
D000485:Allergens; D052179:Antigens, Plant; D000939:Epitopes; D010940:Plant Proteins; D011994:Recombinant Proteins; C061312:Bet v 1 allergen, Betula