Abstract Protein-polymer conjugates are used to treat several diseases. PEGylation, i.e. the modification with poly(ethylene glycol) (PEG) is the currently used strategy. However, due to its non-biodegradability, the design of effective and degradable conjugates is of both academic and industry potential. We present the preparation and studies of the activity and stability of novel biodegradable myoglobin-polyphosphoester conjugates. Poly(ethyl ethylene phosphate) (PEEP) is a water-soluble polyphosphoester, which had been reported to be biocompatible and biodegradable. PEEP is a promising candidate as a degradable substitute for the “gold standard” PEG, which can cause long-term effects, as it is not degradable. PEEPylated conjugates with a variable degree of polymer grafting were synthesized, characterized (with online triple detection size exclusion chromatography, mass spectrometry, and gel electrophoresis), and compared with PEGylated analogs. We highlight differences in how the structure, the number, and the length of the polymer influence the properties of the conjugates. Overall, the analyses conducted (including activity assay, calorimetry, and fluorimetry measurements) show that the covalent attachment of the polymer does not irrevocably affect the protein’s features under physiological conditions, suggesting the potential of this new class of polymers for the design of a new generation of fully degradable conjugates.

中文翻译：

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蛋白质的 PPEylation：肌红蛋白-聚磷酸酯偶联物的合成、活性和稳定性

摘要 蛋白质-聚合物偶联物用于治疗多种疾病。PEG化，即用聚(乙二醇)(PEG)修饰是当前使用的策略。然而，由于其不可生物降解性，有效且可降解的偶联物的设计具有学术和工业潜力。我们介绍了新型可生物降解肌红蛋白-聚磷酸酯偶联物的活性和稳定性的制备和研究。聚（乙基磷酸乙烯酯）（PEEP）是一种水溶性聚磷酸酯，据报道具有生物相容性和生物可降解性。PEEP 是“黄金标准”PEG 的可降解替代品，是一种很有前途的候选物，因为它不可降解，因此会产生长期影响。合成了具有不同聚合物接枝度的 PEEPylated 缀合物，表征（使用在线三重检测尺寸排阻色谱、质谱和凝胶电泳），并与聚乙二醇化类似物进行比较。我们强调了聚合物的结构、数量和长度如何影响共轭物性质的差异。总体而言，所进行的分析（包括活性测定、量热法和荧光法测量）表明，聚合物的共价连接在生理条件下不会不可逆转地影响蛋白质的特征，这表明这类新型聚合物具有设计新的潜力产生完全可降解的结合物。并且聚合物的长度影响缀合物的性质。总体而言，所进行的分析（包括活性测定、量热法和荧光法测量）表明，聚合物的共价连接在生理条件下不会不可逆转地影响蛋白质的特征，这表明这类新型聚合物具有设计新的潜力产生完全可降解的结合物。并且聚合物的长度影响缀合物的性质。总体而言，所进行的分析（包括活性测定、量热法和荧光法测量）表明，聚合物的共价连接在生理条件下不会不可逆转地影响蛋白质的特征，这表明这类新型聚合物具有设计新的潜力产生完全可降解的结合物。