Control of protein activity is a critical issue for human health and treatment of disease. Conjugation to synthetic polymers is an effective method to control protein activity at different levels, providing new opportunities for therapy, molecular diagnostics, and tissue engineering. In this work we generated a mutant pyrophosphatase (PPase) with a substituted cysteine residue near the active site by site-directed mutagenesis. This was used for conjugation to sulfhydryl modiﬁer p-chloromercuribenzoate (PCMB) and to pyridyl disulﬁde-functionalized poly(2-hydroxyethyl methacrylate) (pHEMA) via the “grafting to” method, resulting in a clear and reversible decrease or entire loss of catalytic activity of PPase due to conformational change. This approach provides a new strategy for efficient control of protein activity at different levels by site-speciﬁc conjugation of a small molecule and a polymer. We also prepared protein–polymer conjugates via the “grafting from” method by visible light assisted reversible addition-fragmentation chain transfer (RAFT) polymerization at ambient temperature. This polymerization is fast and can be conveniently controlled via irradiation time. By site-specific polymerization of N-isopropyl acrylamide (NIPAAm) from the protein surface, activity is retained and in certain cases provides a conjugate with on-off-switchable properties in response to temperature.<br/><br/>This work was financially supported by the National Science Fund for Distinguished Young Scholars (21125418) and the National Natural Science Foundation of China (21334004, 21474071).

Synthesis of protein-polymer conjugates with controllable activity through site-specific conjugation

249th National Meeting (2015)

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