英国曼彻斯特大学Leigh, David A.团队开发了一个读取磁带的分子棘轮。相关研究成果发表在2022年10月19日出版的《自然》。
细胞以一种类似图灵机器的方式处理信息，自主地从分子磁带读取数据并将其转换为输出。研究人员已经描述了能够衍生螺纹聚合物的随机处理大环催化剂，以及将构建块从分子链依次转移到生长的低聚物的轮烷。然而，可以读取和/或写入存储在人造分子磁带上的信息的合成小分子机器仍待研究。
该文中，研究人员报道了一种分子棘轮，其中冠醚（“读取头”）通过化学燃料的脉冲从溶液中泵入编码的分子链（“磁带”）。进一步的燃料脉冲通过能量棘轮机制，将宏观循环通过磁带的一系列隔室进行传输，然后将其释放回链的另一端。在其定向运输过程中，冠醚根据沿途结合位点的立体化学改变构象。这使编程到磁带中的立体化学信息序列通过改变的圆二色性响应以非破坏性的方式作为数字串读出。
这一概念的例证是读取具有平衡三位数字串（'trits'23）、1,0、+1和1,0,1的分子带。小分子棘轮是一种有限状态自动机，图灵机在一个方向上通过字符串编码的状态序列移动，根据占用的机器状态给出输出是一种特例。它通过人工纳米机器沿着分子磁带的定向运动，为信息的读取和最终写入开辟了道路。
附：英文原文
Title: A tape-reading molecular ratchet
Author: Ren, Yansong, Jamagne, Romain, Tetlow, Daniel J., Leigh, David A.
Issue&Volume: 2022-10-19
Abstract: Cells process information in a manner reminiscent of a Turing machine1, autonomously reading data from molecular tapes and translating it into outputs2,3. Randomly processive macrocyclic catalysts that can derivatise threaded polymers have been described4,5, as have rotaxanes that transfer building blocks in sequence from a molecular strand to a growing oligomer6,7,8,9,10. However, synthetic small-molecule machines that can read and/or write information stored on artificial molecular tapes remain elusive11,12,13. Here we report on a molecular ratchet in which a crown ether (the ‘reading head’) is pumped from solution onto an encoded molecular strand (the ‘tape’) by a pulse14,15 of chemical fuel16. Further fuel pulses transport the macrocycle through a series of compartments of the tape via an energy ratchet14,17,18,19,20,21,22 mechanism, before releasing it back to bulk off the other end of the strand. During its directional transport, the crown ether changes conformation according to the stereochemistry of binding sites along the way. This allows the sequence of stereochemical information programmed into the tape to be read out as a string of digits in a non-destructive manner through a changing circular dichroism response. The concept is exemplified by the reading of molecular tapes with strings of balanced ternary digits (‘trits’23), 1,0,+1 and 1,0,1. The small-molecule ratchet is a finite-state automaton: a special case24 of a Turing machine that moves in one direction through a string-encoded state sequence, giving outputs dependent on the occupied machine state25,26. It opens the way for the reading—and ultimately writing—of information using the powered directional movement of artificial nanomachines along molecular tapes.
DOI: 10.1038/s41586-022-05305-9
Source: https://www.nature.com/articles/s41586-022-05305-9