Directed Chemical Evolution with an Outsized Genetic Code.
Directed Chemical Evolution with an Outsized Genetic Code.
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DOI：
10.1371/journal.pone.0154765
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Harbury PB
中科院分区：
文献类型：
--
作者：
Krusemark CJ;Tilmans NP;Brown PO;Harbury PB
第一次证明大分子可以在试管中进化是在25年前。这一突破意味着数十亿年的偶然发现和改进可以压缩到几周内，并提供了一个强大的工具，现在主导着蛋白质工程的各个方面。一个挑战是将这一科学进步扩展到合成化学领域：使非生物分子能够定向进化。这个问题已经从许多方面得到了解决。这些包括扩展天然遗传密码以包括非天然氨基酸，工程化聚酮化合物和多肽脱氢酶以产生新的产物，以及用DNA标记组合化学文库。重要的是，仍然没有定向蛋白质进化的小分子类似物，即在连续世代中优化合成小分子的复杂（≥ 10^9多样性）群体的经证实的方法。我们提出了实现这一目标的一个关键进展：从大化学字母表中遗传编程合成小分子库的工具。这种方法可以容纳比自然界中任何一种都大一到两个数量级的字母，并促进它们所创造的化学空间内的进化。这对于小分子来说至关重要，小分子是由众多且高度不同的化学碎片组成的。我们报告了一个利用超大遗传密码的概念验证化学进化实验，并证明了适应性特征可以从最初的小分子群体传递到该群体的曾孙。这些结果确立了通过加速进化工程化合成小分子的实际可行性。
The first demonstration that macromolecules could be evolved in a test tube was reported twenty-five years ago. That breakthrough meant that billions of years of chance discovery and refinement could be compressed into a few weeks, and provided a powerful tool that now dominates all aspects of protein engineering. A challenge has been to extend this scientific advance into synthetic chemical space: to enable the directed evolution of abiotic molecules. The problem has been tackled in many ways. These include expanding the natural genetic code to include unnatural amino acids, engineering polyketide and polypeptide synthases to produce novel products, and tagging combinatorial chemistry libraries with DNA. Importantly, there is still no small-molecule analog of directed protein evolution, i.e. a substantiated approach for optimizing complex (≥ 10^9 diversity) populations of synthetic small molecules over successive generations. We present a key advance towards this goal: a tool for genetically-programmed synthesis of small-molecule libraries from large chemical alphabets. The approach accommodates alphabets that are one to two orders of magnitude larger than any in Nature, and facilitates evolution within the chemical spaces they create. This is critical for small molecules, which are built up from numerous and highly varied chemical fragments. We report a proof-of-concept chemical evolution experiment utilizing an outsized genetic code, and demonstrate that fitness traits can be passed from an initial small-molecule population through to the great-grandchildren of that population. The results establish the practical feasibility of engineering synthetic small molecules through accelerated evolution.