School of Chemistry, University of Manchester, Manchester, UK.
Organic Synthesis and Mass Spectrometry Laboratory, Interdisciplinary Center for Mass Spectrometry (CISMa), University of Mons, Mons, Belgium.
Nat Nanotechnol. 2018 May;13(5):381-385. doi: 10.1038/s41565-018-0105-3. Epub 2018 Apr 2.
Biomolecular machines perform types of complex molecular-level tasks that artificial molecular machines can aspire to. The ribosome, for example, translates information from the polymer track it traverses (messenger RNA) to the new polymer it constructs (a polypeptide) . The sequence and number of codons read determines the sequence and number of building blocks incorporated into the biomachine-synthesized polymer. However, neither control of sequence nor the transfer of length information from one polymer to another (which to date has only been accomplished in man-made systems through template synthesis) is easily achieved in the synthesis of artificial macromolecules. Rotaxane-based molecular machines have been developed that successively add amino acids (including β-amino acids ) to a growing peptide chain by the action of a macrocycle moving along a mono-dispersed oligomeric track derivatized with amino-acid phenol esters. The threaded macrocycle picks up groups that block its path and links them through successive native chemical ligation reactions to form a peptide sequence corresponding to the order of the building blocks on the track. Here, we show that as an alternative to translating sequence information, a rotaxane molecular machine can transfer the narrow polydispersity of a leucine-ester-derivatized polystyrene chain synthesized by atom transfer radical polymerization to a molecular-machine-made homo-leucine oligomer. The resulting narrow-molecular-weight oligomer folds to an α-helical secondary structure that acts as an asymmetric catalyst for the Juliá-Colonna epoxidation of chalcones.
生物分子机器执行着各种复杂的分子级任务，这是人工分子机器所渴望实现的。例如，核糖体将其遍历的聚合物轨道（信使 RNA）上的信息翻译到它构建的新聚合物（多肽）中。读取的密码子的序列和数量决定了生物机器合成聚合物中包含的构建块的序列和数量。然而，无论是对序列的控制还是将长度信息从一种聚合物转移到另一种聚合物（迄今为止，只有在人造系统中通过模板合成才能实现），在人工大分子的合成中都不容易实现。已经开发出基于轮烷的分子机器，通过大环沿衍生有氨基酸苯酚酯的单分散寡聚物轨道的移动，成功地将氨基酸（包括β-氨基酸）连续添加到生长的肽链中。穿线的大环会拾取阻挡其路径的基团，并通过连续的天然化学连接反应将它们连接起来，形成与轨道上构建块顺序相对应的肽序列。在这里，我们表明，作为替代翻译序列信息的方法，轮烷分子机器可以将通过原子转移自由基聚合合成的亮氨酸酯衍生聚苯乙烯链的窄多分散性转移到分子机器制造的同亮氨酸低聚物上。得到的窄分子量低聚物折叠成α-螺旋二级结构，作为 Jul ía-Colonna 查尔酮环氧化反应的不对称催化剂。
