کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5917023 | 1163768 | 2014 | 8 صفحه PDF | دانلود رایگان |
- The extracellular domains of hu/ca FcÉRIα were expressed in Pichia pastoris.
- The binding of IgE variants to hu/ca FcÉRIα was assessed by β-hexosaminidase release.
- The kinetic analysis revealed the interaction of each IgE variant with hu/ca FcÉRIα.
- We had obtained kinetic constants of ca IgE and its variants for hu/ca FcÉRIα by SPR.
- Kinetic data confirms the observed effects of key residues in β-hexosaminidase assay.
The interaction of immunoglobulin E (IgE) antibodies with the high-affinity receptor (FcÉRI) is important in anti-parasitic immunity and plays a central role in allergic responses. It has been shown that the human CÉ3 domains comprise the binding sites for FcÉRIα and crystal structure determination has shown that amino acids in four sites contribute to the high affinity of the interaction. The role of homologous residues within canine IgE-Fc, i.e. amino acids located at CÉ2-CÉ3 interface (residues 332-337), loop BC (residues 362-365), loop DE (residues 393-396), and loop FG (residues 424-427) in canine CÉ3 domain were targeted by site-specific mutagenesis. The functional consequences of the mutations to support (i) IgE-mediated, antigen-induced release of β-hexosaminidase from RBL cells transfected with canine or human FcÉRIα and (ii) the affinity of the mutants for the soluble extracellular domain of the α-chain expressed in Pichia pastoris were determined by Surface Plasmon Resonance (SPR). Kinetic analysis supports the observed effects of IgE mutations on stimulus secretion coupling. Potential applications of this study, leading to the generation of an IgE variant with a disabled FcÉRIα binding site, are discussed.
Journal: Molecular Immunology - Volume 57, Issue 2, February 2014, Pages 111-118