2R56

Crystal Structure of a Recombinant IgE Fab Fragment in Complex with Bovine Beta-Lactoglobulin Allergen

Summary for 2R56

• Entry DOI: 10.2210/pdb2r56/pdb
• Descriptor: Beta-lactoglobulin, IgE Fab Fragment, light chain, IgE Fab Fragment, heavy chain, ... (4 entities in total)
• Functional Keywords: allergen, ige, epitope, immunocomplex, lipocalin, fab, milk protein, polymorphism, retinol-binding, secreted, transport, immune system
• Biological source: Bos taurus (cattle); More
• Cellular location: Secreted: P02754
• Total number of polymer chains: 6
• Total formula weight: 130749.61

Authors

Niemi, M.,Kallio, J.M.,Hakulinen, N.,Rouvinen, J. (deposition date: 2007-09-03, release date: 2007-11-13, Last modification date: 2024-11-06)

Primary citation

Niemi, M.,Jylha, S.,Laukkanen, M.L.,Soderlund, H.,Makinen-Kiljunen, S.,Kallio, J.M.,Hakulinen, N.,Haahtela, T.,Takkinen, K.,Rouvinen, J.
Molecular interactions between a recombinant IgE antibody and the beta-lactoglobulin allergen.
Structure, 15:1413-1421, 2007

PubMed Abstract: Allergies are caused by the immune reaction to commonly harmless proteins, allergens. This reaction is typified by immunoglobulin E (IgE) antibodies. We report the crystal structure of an IgE Fab fragment in complex with beta-lactoglobulin (BLG), one of the major allergens of bovine milk. The solved structure shows how two IgE/Fab molecules bind the dimeric BLG. The epitope of BLG consists of six different short fragments of the polypeptide chain, which are located especially in the beta strands, covering a flat area on the allergen surface. All six CDR (complementary-determining region) loops of the IgE Fab participate in the binding of BLG. The light chain CDR loops are responsible for the binding of the flat beta sheet region of BLG. The IgE epitope is different from common IgG epitopes that are normally located in the exposed loop regions of antigens and observed also in the two recently determined allergen-IgG complexes.

PubMed: 17997967
DOI: 10.1016/j.str.2007.09.012

Experimental method

X-RAY DIFFRACTION (2.8 Å)