In Situ Formation of Protein–Polymer Conjugates through Reversible Addition Fragmentation Chain Transfer Polymerization

Abstract

A good place for rafting: Bovine serum albumin (BSA) was site‐specifically modified with a reversible addition fragmentation chain transfer (RAFT) agent and used in γ‐radiation‐initiated polymerization of oligo(ethylene glycol) acrylate. Well‐defined polymer chains were formed at the RAFT agent conjugation site of BSA leading to the generation of BSA–polymer conjugates in situ.

Responsive Polymer‐Protein Bioconjugates Prepared by RAFT Polymerization and Copper‐Catalyzed Azide‐Alkyne Click Chemistry

“…However, purification was made possible by the temperatureresponsive nature of the immobilized polymer; upon heating above the lower critical solution temperature (LCST) of the PNIPAM, only the conjugated BSA precipitated from aqueous solution, thereby facilitating separation from the unreacted protein (Figure 2, inset). [12] To increase the number of available conjugation sites, mild reduction of BSA was accomplished with tris(2-carboxyethyl)phosphine hydrochloride (TCEP). [9] Analysis by Ellman's assay indicated an increase in the average thiol content per protein from approximately 0.45 to 3, consistent with the reduction of a surface disulfide and the oxidized residues at Cys-34.…”

“…[7] While the former has proven highly successful for the synthesis of polymerprotein conjugates, [8][9][10] the adoption of RAFT has been considerably more gradual, [11][12][13] despite the absence of a metal catalyst and facile amenability to aqueous, nondenaturing media. [14] For the grafting reaction, a wide variety of coupling strategies has been considered including reductive alkylation, [15] thiol-maleimide Michael addition, [16] and oxime formation.…”

Polymers with Well‐Defined End Groups via RAFT – Synthesis, Applications and Post modifications

“…Recently, several research groups have started to employ the RAFT technique toward the preparation of biomolecule-polymer conjugates [24][25][26][27]. The combined properties of polymer and biomolecules may lead to unique properties and may subsequently be employed in applications such as affinity separations, immunoassays, enzyme recovery and bioengineering [25].…”

Fabrication of a Thermoresponsive Biohybrid Double Hydrophilic Block Copolymer by a Cofactor Reconstitution Approach

“…addition-fragmentation chain transfer (RAFT) polymerization, which allow for the direct synthesis of polymerprotein conjugates from protein-based ATRP macroinitiators [18][19][20] and macro-RAFT mediating agents [5,9,21] in the presence of suitable monomers. Proteins modified with hydrophobic and hydrophilic polymer segments can be considered as biohybrid amphiphilic and double hydrophilic block copolymers (DHBCs), respectively.…”