Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, 14195 Berlin, Germany.
Biomacromolecules. 2021 Apr 12;22(4):1406-1416. doi: 10.1021/acs.biomac.0c01627. Epub 2021 Apr 1.
Since several decades, PEGylation is known to be the clinical standard to enhance pharmacokinetics of biotherapeutics. In this study, we introduce polyglycerol (PG) of different lengths and architectures (linear and hyperbranched) as an alternative polymer platform to poly(ethylene glycol) (PEG) for half-life extension (HLE). We designed site-selective N-terminally modified PG-protein conjugates of the therapeutic protein anakinra (IL-1ra, Kineret) and compared them systematically with PEG analogues of similar molecular weights. Linear PG and PEG conjugates showed comparable hydrodynamic sizes and retained their secondary structure, whereas binding affinity to IL-1 receptor 1 decreased with increasing polymer length, yet remained in the low nanomolar range for all conjugates. The terminal half-life of a 40 kDa linear PG-modified anakinra was extended 4-fold compared to the unmodified protein, close to its PEG analogue. Our results demonstrate similar performances of PEG- and PG-anakinra conjugates and therefore highlight the outstanding potential of polyglycerol as a PEG alternative for half-life extension of biotherapeutics.
几十年来，聚乙二醇（PEG）化被认为是提高生物治疗药物药代动力学的临床标准。在这项研究中，我们引入了具有不同长度和结构（线性和支化）的聚甘油（PG）作为聚乙二醇（PEG）的替代聚合物平台，以延长半衰期（HLE）。我们设计了具有位点选择性的 N-末端修饰的 PG-蛋白质缀合物，即治疗蛋白阿那白滞素（IL-1ra，Kineret），并将其与具有相似分子量的 PEG 类似物进行了系统比较。线性 PG 和 PEG 缀合物显示出相当的流体力学大小，并保留了其二级结构，而与 IL-1 受体 1 的结合亲和力随聚合物长度的增加而降低，但所有缀合物仍保持在低纳摩尔范围内。与未修饰的蛋白质相比，40 kDa 线性 PG 修饰的阿那白滞素的末端半衰期延长了 4 倍，接近其 PEG 类似物。我们的结果表明 PEG-和 PG-阿那白滞素缀合物具有相似的性能，因此突出了聚甘油作为生物治疗药物半衰期延长的 PEG 替代物的巨大潜力。
