Synthesis of Modular Brush Polymer-Protein Hybrids Using Diazotransfer and Copper Click Chemistry.

TitleSynthesis of Modular Brush Polymer-Protein Hybrids Using Diazotransfer and Copper Click Chemistry.
Publication TypeJournal Article
Year of Publication2018
AuthorsLA Navarro, DL French, and S Zauscher
JournalBioconjugate Chemistry
Volume29
Issue8
Start Page2594
Pagination2594 - 2605
Date Published07/2018
Abstract

Proteoglycans are important brush-like biomacromolecules, which serve a variety of functions in the human body. While protein-bottlebrush hybrids are promising proteoglycan mimics, many challenges still exist to robustly produce such polymers. In this paper, we report the modular synthesis of protein-brush hybrids containing elastin-like polypeptides (ELP) as model proteins by copper-catalyzed azide-alkyne cycloaddition. We exploit the recently discovered imidazole-1-sulfonyl azide (ISA) in a diazotransfer reaction to introduce an N-terminal azide onto an ELP. Next, we use a click reaction to couple the azido-ELP to an alkyne-terminated amine-rich polymer followed by a second diazotransfer step to produce an azide-rich backbone that serves as a scaffold. Finally, we used a second click reaction to graft alkyne-terminated poly(oligoethylene glycol methacrylate) (POEGMA) bristles to the azide-rich backbone to produce the final protein-bottlebrush hybrid. We demonstrate the effectiveness of this synthetic path at each step through careful characterization with 1H NMR, FTIR, GPC, and diagnostic test reactions on SDS-PAGE. Final reaction products could be consistently obtained for a variety of different molecular weight backbones with final total grafting efficiencies around 70%. The high-yielding reactions employed in this highly modular approach allow for the synthesis of protein-bottlebrush hybrids with different proteins and brush polymers. Additionally, the mild reaction conditions used have the potential to avoid damage to proteins during synthesis.

DOI10.1021/acs.bioconjchem.8b00309
Short TitleBioconjugate Chemistry