Structure-activity relationships of a peptide inhibitor of the human FcRn:human IgG interaction
Adam R Mezo1, Kevin A McDonnell, Alfredo Castro
1Syntonix Pharmaceuticals, Inc., 9 Fourth Avenue, Waltham, MA 02451, USA. amezo@syntnx.com
Abstract:
A family of five peptides was previously discovered by phage display techniques that binds to the human neonatal Fc receptor (FcRn) and inhibits the human IgG:human FcRn protein-protein interaction [Proc. Nat. Acad. Sci. U.S.A.2008, 105, 2337-2342]. The consensus peptide motif consists of the sequence GHFGGXY where X is preferably a hydrophobic amino acid, and also includes a disulfide bridge enclosing 11-amino acids in varying positions about the consensus sequence. We describe herein the structure-activity relationships of one of the five peptides in binding to FcRn using surface plasmon resonance and IgG:FcRn competition ELISA assays. Modifications of the peptide length, cyclization, and the incorporation of amino acid substitutions and dipeptide mimetics were studied. The most potent analogs exhibited a 50- to 100-fold improvement of in vitro activity over that of the phage-identified peptide sequence.
More Related Videos
Related Concept Videos
Protein-protein Interfaces
Drug-Receptor Interactions
Several parameters, such as the drug's affinity for its receptor and its efficacy, which is its ability to activate the receptor, determine the drug's effect on the tissue.
Drug-Receptor Interaction: Agonist
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous ligand's action.


