Identification Of The Linear Epitope For Fc-Binding On The Bovine Igg2 Fc Receptor (Bofc Gamma 2r) Using Synthetic Peptides

To identify the linear epitope for Fe-binding on the bovine IgG2 Fe receptor (boFc gamma 2R), peptides derived from the membrane-distal extracellular domain (EC1) of boFc gamma 2R corresponding to the homologous region of human Fc alpha RI were synthesized. Binding of bovine IgG2 to the different peptides was tested by Dot-blot assay, and the peptide showing maximal binding was further modified by truncation and mutation. The minimum effective peptide (82)FIGV(85) located in the putative F-G loop of the EC1 domain was found to bind bovine IgG2 specifically and inhibit the binding of bovine IgG2 to the receptor. The Phe(82), Ile(83) and Val(85) residues within the linear epitope were shown to be critical for IgG2-binding. Such functional epitope peptide should be very useful for understanding the IgG-Fc gamma interaction and development of FcR-targeting drugs. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.