Single-chain heteropolymers transport protons selectively and rapidly
Single-chain heteropolymers transport protons selectively and rapidly
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单链杂聚物选择性和快速地传输质子
DOI：
10.1038/s41586-019-1881-0
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发表时间：
2020-01-09
期刊：
影响因子：
64.8
通讯作者：
Xu, Ting
中科院分区：
文献类型：
--
作者：
Jiang, Tao;Hall, Aaron;Xu, Ting
精确的蛋白质测序和折叠被认为产生了自然通道的结构和化学多样性（1,2），这两者对于合成实现与自然系统相当的质子传输性能至关重要。几何上定义的通道已经用多肽、dna、碳纳米管、序列定义的聚合物和有机框架制造出来（3-13）。然而，这些通道都无法与自然通道的性能相媲美。本研究表明，在不形成原子结构通道的情况下，基于四单体的随机异聚物（RHPs）（14）可以模拟膜蛋白，并以与天然质子通道相似的速率在脂质双分子层上表现出选择性质子运输。对RHP中单体分布的统计控制导致疏水性的节段异质性，这有助于将单个RHPs插入脂质双层。它还会产生含有极性单体的双层跨越段，促进质子传输的氢键链的形成（15,16）。我们的研究证明了RHP链之间的统计相似性和单体化学多样性提供的模块化所带来的适应性在异质系统中实现统一行为的重要性。我们的结果也验证了统计随机性作为一种未探索的方法，以可预测的方式在单聚合物链水平上实现蛋白质样行为。
Precise protein sequencing and folding are believed to generate the structure and chemical diversity of natural channels(1,2), both of which are essential to synthetically achieve proton transport performance comparable to that seen in natural systems. Geometrically defined channels have been fabricated using peptides, DNAs, carbon nanotubes, sequence-defined polymers and organic frameworks(3-13). However, none of these channels rivals the performance observed in their natural counterparts. Here we show that without forming an atomically structured channel, four-monomer-based random heteropolymers (RHPs)(14) can mimic membrane proteins and exhibit selective proton transport across lipid bilayers at a rate similar to those of natural proton channels. Statistical control over the monomer distribution in an RHP leads to segmental heterogeneity in hydrophobicity, which facilitates the insertion of single RHPs into the lipid bilayers. It also results in bilayer-spanning segments containing polar monomers that promote the formation of hydrogen-bonded chains(15,16) for proton transport. Our study demonstrates the importance of the adaptability that is enabled by statistical similarity among RHP chains and of the modularity provided by the chemical diversity of monomers, to achieve uniform behaviour in heterogeneous systems. Our results also validate statistical randomness as an unexplored approach to realize protein-like behaviour at the single-polymer-chain level in a predictable manner.