Sortase-Catalyzed Initiator Attachment Enables High Yield Growth of a Stealth Polymer from the C Terminus of a Protein

TitleSortase-Catalyzed Initiator Attachment Enables High Yield Growth of a Stealth Polymer from the C Terminus of a Protein
Publication TypeJournal Article
Year of Publication2013
AuthorsQi, Y, Amiram, M, Gao, W, McCafferty, DG, Chilkoti, A
JournalMacromolecular Rapid Communications
Volume34
Issue15
Pagination1256–1260
Date Published07/2013
Abstract

Conventional methods for synthesizing protein/peptide–polymer conjugates, as a means to improve the pharmacological properties of therapeutic biomolecules, typically have drawbacks including low yield, non-trivial separation of conjugates from reactants, and lack of site- specificity, which results in heterogeneous products with significantly compromised bioactivity. To address these limitations, the use of sortase A from Staphylococcus aureus is demonstrated to site-specifically attach an initiator solely at the C-terminus of green fluorescent protein (GFP), followed by in situ growth of a stealth polymer, poly(oligo(ethylene glycol) methyl ether methacrylate) by atom transfer radical polymerization (ATRP). Sortase-catalyzed initiator attachment proceeds with high specificity and near-complete (≈95%) product conversion. Subsequent in situ ATRP in aqueous buffer produces 1:1 stoichiometric conjugates with >90% yield, low dispersity, and no denaturation of the protein. This approach introduces a simple and useful method for high yield synthesis of protein/peptide–polymer conjugates.

DOI10.1002/marc.201300460
Short TitleMacromol. Rapid Commun.