Transforming protein-polymer conjugate purification by tuning protein solubility
Transforming protein-polymer conjugate purification by tuning protein solubility
复制标题
DOI：
10.1038/s41467-019-12612-9
复制
发表时间：
2019-10-17
影响因子：
16.6
通讯作者：
Russell, Alan J.
中科院分区：
文献类型：
--
作者：
Baker, Stefanie L.;Munasinghe, Aravinda;Russell, Alan J.
几乎所有的商业蛋白质都是用硫酸铵沉淀法提纯的。蛋白质-聚合物结合物是由纯起始材料合成的，从聚合物、天然蛋白质和异构体中分离结合物的斗争已经困扰了科学家几十年。我们发现共价聚合物吸附对蛋白质在盐溶液中的溶解度有转化作用。在这里，蛋白质-聚合物与各种聚合物、接枝密度和聚合物长度的结合是通过原子转移自由基聚合产生的。带电聚合物增加了共轭在硫酸铵中的溶解度，即使在100%饱和状态下也完全防止沉淀。原子分子动力学模拟表明，这种影响是由两性离子聚合物的反聚电解质效应驱动的。不带电荷的聚合物表现出与聚合物长度相关的降低的溶解度。然后，盐析的差异被用来简单地将结合物和天然蛋白质的混合物纯化成单一物种。通过聚合物偶联来提高蛋白质在盐溶液中的溶解度可能会导致蛋白质-聚合物偶联物的许多新的应用。
Almost all commercial proteins are purified using ammonium sulfate precipitation. Protein-polymer conjugates are synthesized from pure starting materials, and the struggle to separate conjugates from polymer, native protein, and from isomers has vexed scientists for decades. We have discovered that covalent polymer attachment has a transformational effect on protein solubility in salt solutions. Here, protein-polymer conjugates with a variety of polymers, grafting densities, and polymer lengths are generated using atom transfer radical polymerization. Charged polymers increase conjugate solubility in ammonium sulfate and completely prevent precipitation even at 100% saturation. Atomistic molecular dynamic simulations show the impact is driven by an anti-polyelectrolyte effect from zwitterionic polymers. Uncharged polymers exhibit polymer length-dependent decreased solubility. The differences in salting-out are then used to simply purify mixtures of conjugates and native proteins into single species. Increasing protein solubility in salt solutions through polymer conjugation could lead to many new applications of protein-polymer conjugates.