SG1-Functionalized Peptides as Precursors for Polymer−Peptide Conjugates: A Straightforward Approach
Résumé
We report here a straightforward route to polymer?peptide conjugates via the convenient synthesis of SG1-functionalized peptides able to initiate nitroxide-mediated polymerization (NMP). The NMP initiator SG1-functionalized peptide (SG1-GGGWIKVAV) was prepared by solid-phase peptide synthesis (SPPS) using an automated synthesizer, with a last step consisting of reaction between the carboxylic acid function of the MAMA-SG1 (BlocBuilder) alkoxyamine with the peptide terminal amine in the presence of benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate (PyBOP) as coupling agent. The resulting SG1-functionalized resin-attached peptide was used to perform the controlled NMP of styrene, leading after trifluoroacetic acid cleavage to the corresponding polystyrene?peptide conjugate. The latter was thoroughly characterized by UV spectrometry, gel permeation chromatography (GPC), 1H NMR, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).