With more than 20 Food and Drug Administration (FDA)-approved poly (ethylene glycol) (PEG) modified drugs on the market, PEG is the gold standard polymer in bioconjugation. The coupling improves stability, efficiency and can prolong blood circulation time of therapeutic proteins. Even though PEGylation is described as non-toxic and non-immunogenic, reports accumulate with data showing allergic reactions to PEG. Since PEG is not only applied in therapeutics, but can also be found in foods and cosmetics, anti-PEG-antibodies can occur even without a medical treatment. Hypersensitivity to PEG thereby can lead to a reduced drug efficiency, fast blood clearance and in rare cases anaphylactic reactions. Therefore, finding alternatives for PEG is crucial. In this study, we present linear polyglycerol (LPG) for bioconjugation as an alternative polymer to PEG. We report the conjugation of LPG and PEG by click-chemistry to the glycoprotein erythropoietin (EPO), synthesized in a eukaryotic cell-free protein synthesis system. Furthermore, the influence of the polymers on EPOs stability and activity on a growth hormone dependent cell-line was evaluated. The similar characteristics of both bioconjugates show that LPGylation can be a promising alternative to PEGylation.

市场上有超过 20 种食品和药物管理局 (FDA) 批准的聚乙二醇 (PEG) 修饰药物，PEG 是生物偶联聚合物的金标准。这种偶联提高了稳定性和效率，并可以延长治疗性蛋白质的血液循环时间。尽管聚乙二醇化被描述为无毒且无免疫原性，但有关数据显示对聚乙二醇有过敏反应的报告越来越多。由于 PEG 不仅应用于治疗，而且还存在于食品和化妆品中，因此即使不进行药物治疗也可能会产生抗 PEG 抗体。因此，对 PEG 的超敏反应会导致药物效率降低、血液清除速度加快，并且在极少数情况下会导致过敏反应。因此，寻找 PEG 的替代品至关重要。在这项研究中，我们提出用于生物偶联的线性聚甘油 (LPG) 作为 PEG 的替代聚合物。我们通过点击化学报告了 LPG 和 PEG 与在真核无细胞蛋白质合成系统中合成的糖蛋白促红细胞生成素 (EPO) 的结合。此外，还评估了聚合物对 EPO 稳定性和生长激素依赖性细胞系活性的影响。两种生物偶联物的相似特征表明 LPG 化可能是聚乙二醇化的有前途的替代品。