Protein–polymer conjugates combine the unique properties of both proteins and synthetic polymers, making them important materials for biomedical applications. In this work, we synthesized and characterized protein-branched polymer bioconjugates that were precisely designed to retain protein functionality while preventing unwanted interactions. Using chymotrypsin as a model protein, we employed a controlled radical branching polymerization (CRBP) technique utilizing a water-soluble inibramer, sodium 2-bromoacrylate. The green-light-induced atom transfer radical polymerization (ATRP) enabled the grafting of branched polymers directly from the protein surface in the open air. The resulting bioconjugates exhibited a predetermined molecular weight, well-defined architecture, and high branching density. Conformational analysis by SEC-MALS validated the controlled grafting of branched polymers. Furthermore, enzymatic assays revealed that densely grafted polymers prevented protein inhibitor penetration, and the resulting conjugates retained up to 90% of their enzymatic activity. This study demonstrates a promising strategy for designing protein–polymer bioconjugates with tunable sieving behavior, opening avenues for applications in drug delivery and biotechnology.

中文翻译：

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定制的支化聚合物-蛋白质生物缀合物可调节筛分性能

蛋白质-聚合物缀合物结合了蛋白质和合成聚合物的独特性质，使其成为生物医学应用的重要材料。在这项工作中，我们合成并表征了蛋白质支化聚合物生物共轭物，这些生物共轭物经过精确设计，可以保留蛋白质功能，同时防止不必要的相互作用。使用胰凝乳蛋白酶作为模型蛋白质，我们采用了利用水溶性 inibramer 2-溴丙烯酸钠的受控自由基支化聚合 (CRBP) 技术。绿光诱导的原子转移自由基聚合（ATRP）能够在露天直接从蛋白质表面接枝支化聚合物。所得的生物结合物表现出预定的分子量、明确的结构和高支化密度。 SEC-MALS 构象分析验证了支化聚合物的受控接枝。此外，酶测定表明，密集接枝的聚合物可防止蛋白质抑制剂渗透，并且所得缀合物保留了高达 90% 的酶活性。这项研究展示了一种设计具有可调筛分行为的蛋白质-聚合物生物缀合物的有前景的策略，为药物输送和生物技术的应用开辟了途径。