Solid-phase synthesis and cyclization of a large branched peptide from IgG Fc with affinity for FcγRI
✍ Scribed by Joseph M. Sheridan; Gillian M. Hayes; Brian M. Austen
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 162 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1075-2617
No coin nor oath required. For personal study only.
✦ Synopsis
A solid phase approach has been used to synthesize a large branched disulphide peptide from IgG Fc, Ac-
This peptide combines the lower hinge region of IgG and a proximal i-hairpin loop, both implicated in binding to FckRI. Solid phase Tl(tfa) 3 cyclization of the linear branched peptide resulted in a poor yield of cyclic hinge -loop peptide (11%) most likely due to steric hindrance caused by the branch. However, if addition of the branch was preceded by solid phase Tl(tfa) 3 cyclization of the loop, the yield was excellent at 75%. Cyclic hinge -loop peptide was active in displacing IgG2a from FckRI expressed on monocyte cell lines with an IC 50 of 40 vM, whereas the linear form of this peptide was inactive. The Fc hinge -loop peptide demonstrates the potential for a non-mAb high affinity, immunomodulatory ligand for FckRI.