4AKA
IPSE alpha-1, an IgE-binding crystallin
Summary for 4AKA
| Entry DOI | 10.2210/pdb4aka/pdb |
| NMR Information | BMRB: 17405 |
| Descriptor | IL-4-INDUCING PROTEIN (1 entity in total) |
| Functional Keywords | immune system, schistosoma mansoni, immunoglobulin binding |
| Biological source | SCHISTOSOMA MANSONI (BLOOD FLUKE) |
| Total number of polymer chains | 1 |
| Total formula weight | 11981.48 |
| Authors | Meyer, N.H.,Mayerhofer, H.,Tripsianes, K.,Barths, D.,Blindow, S.,Bade, S.,Madl, T.,Frey, A.,Haas, H.,Mueller-Dieckmann, J.,Sattler, M.,Scharmm, G. (deposition date: 2012-02-22, release date: 2013-03-13, Last modification date: 2024-11-13) |
| Primary citation | Meyer, N.H.,Mayerhofer, H.,Tripsianes, K.,Barths, D.,Blindow, S.,Bade, S.,Madl, T.,Frey, A.,Haas, H.,Mueller-Dieckmann, J.,Sattler, M.,Scharmm, G. A Crystallin Fold in the Interleukin-4-Inducing Principle of Schistosoma Mansoni Eggs (Ipse/Alpha-1) Mediates Ige Binding for Antigen-Independent Basophil Activation J.Biol.Chem., 290:22111-, 2015 Cited by PubMed Abstract: The IL-4-inducing principle from Schistosoma mansoni eggs (IPSE/α-1), the major secretory product of eggs from the parasitic worm S. mansoni, efficiently triggers basophils to release the immunomodulatory key cytokine interleukin-4. Activation by IPSE/α-1 requires the presence of IgE on the basophils, but the detailed molecular mechanism underlying activation is unknown. NMR and crystallographic analysis of IPSEΔNLS, a monomeric IPSE/α-1 mutant, revealed that IPSE/α-1 is a new member of the βγ-crystallin superfamily. We demonstrate that this molecule is a general immunoglobulin-binding factor with highest affinity for IgE. NMR binding studies of IPSEΔNLS with the 180-kDa molecule IgE identified a large positively charged binding surface that includes a flexible loop, which is unique to the IPSE/α-1 crystallin fold. Mutational analysis of amino acids in the binding interface showed that residues contributing to IgE binding are important for IgE-dependent activation of basophils. As IPSE/α-1 is unable to cross-link IgE, we propose that this molecule, by taking advantage of its unique IgE-binding crystallin fold, activates basophils by a novel, cross-linking-independent mechanism. PubMed: 26163514DOI: 10.1074/JBC.M115.675066 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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