Controlling the access of proteases to cleavable peptides placed at specific locations within macromolecular architectures represents a powerful strategy for biologically responsive materials design. Here, we report the synthesis of peptide-containing bivalent bottlebrush (co)polymers (BBPs) featuring polyethylene glycol (PEG) and 7-amino-4-methylcoumarin (AMC) pendants on each backbone repeat unit. The AMCs are linked via caspase-3-cleavable peptides which, upon enzymatic cleavage, provide a “turn-on” fluorescence signal due to the release of free AMC. Time-dependent fluorscence measurements demonstrate that the caspase-3-induced peptide cleavage and AMC release from BBPs is strongly dependent on the BBP backbone length and the AMC–peptide linker location within the BBP architecture, revealing fundamental insights into the interactions of enzymes with BBPs.

中文翻译：

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Caspase-3 响应性荧光二价洗瓶刷聚合物

控制蛋白酶与位于大分子结构内特定位置的可裂解肽的接触代表了生物响应材料设计的强大策略。在这里，我们报告了含肽二价瓶刷（共）聚合物（BBP）的合成，该聚合物在每个主链重复单元上具有聚乙二醇（PEG）和7-氨基-4-甲基香豆素（AMC）悬垂物。 AMC 通过 caspase-3 可裂解肽连接，在酶裂解后，由于游离 AMC 的释放而提供“开启”荧光信号。时间依赖性荧光测量表明，Caspase-3 诱导的肽裂解和 BBP 中 AMC 的释放强烈依赖于 BBP 主链长度和 BBP 结构内的 AMC-肽接头位置，揭示了酶与 BBP 相互作用的基本见解。