Genetically programmed chiral organoborane synthesis.
Genetically programmed chiral organoborane synthesis.
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DOI：
10.1038/nature24996
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发表时间：
2017-12-07
期刊：
影响因子：
64.8
通讯作者：
Arnold FH
中科院分区：
文献类型：
--
作者：
Kan SBJ;Huang X;Gumulya Y;Chen K;Arnold FH
酶工程和设计的最新进展将自然界的催化能力扩展到了生物学上的新功能。然而，这些工程酶中只有一部分可以在生命系统中发挥作用。在细胞环境中寻找形成生物学中未发现的化学键的酶途径尤其困难，因为这不仅取决于新酶活性的发现，还取决于对所需转化具有足够反应性且在体内稳定的试剂的发现。在这里，我们报告了用于在细菌中生产手性有机硼烷的完全基因编码平台的发现、进化和推广。研究发现，携带来自红热菌 (Rhodothermus marinus) 的野生型细胞色素 c (Rma cyt c) 的大肠杆菌在硼烷-刘易斯碱复合物存在的情况下，通过卡宾插入 B-H 键形成碳-硼键。 Rma cyt c 在细菌催化剂中的定向进化提供了获得 16 种新型手性有机硼烷的途径。该催化剂适用于克级生物合成，提供高达 15300 次转换、6100 h–1 转换频率、99:1 对映体比率 (e.r.) 和 100% 化学选择性。生物催化剂的对映体偏好也可以转换以提供有机硼烷产物的任一对映体。这些蛋白质是在全细胞催化剂的背景下进化而来的，在全细胞系统中比纯化形式更活跃。这项研究建立了一个 DNA 编码且易于设计的硼酸化细菌平台；工程的完成速度可以与化学合成方法的发展相媲美，并且能够实现比同类转化的已知手性催化剂高两个数量级（超过 400 倍）的转化率。这种操纵细胞中硼的可调方法开辟了生命系统中硼化学的全新世界。
Recent advances in enzyme engineering and design have expanded nature’s catalytic repertoire to functions that are new to biology. Yet only a subset of these engineered enzymes can function in living systems. Finding enzymatic pathways that forge chemical bonds not found in biology is particularly difficult in the cellular environment, as this hinges on the discovery not only of new enzyme activities but also reagents that are simultaneously sufficiently reactive for the desired transformation and stable in vivo. Here we report the discovery, evolution, and generalisation of a fully genetically-encoded platform for producing chiral organoboranes in bacteria. Escherichia coli harbouring wild-type cytochrome c from Rhodothermus marinus (Rma cyt c) were found to form carbon–boron bonds in the presence of borane-Lewis base complexes, through carbene insertion into B–H bonds. Directed evolution of Rma cyt c in the bacterial catalyst provided access to 16 novel chiral organoboranes. The catalyst is suitable for gram scale biosynthesis, offering up to 15300 turnovers, 6100 h–1 turnover frequency, 99:1 enantiomeric ratio (e.r.), and 100% chemoselectivity. The enantio-preference of the biocatalyst could also be switched to provide either enantiomer of the organoborane products. Evolved in the context of whole-cell catalysts, the proteins were more active in the whole-cell system than in purified forms. This study establishes a DNA-encoded and readily engineered bacterial platform for borylation; engineering can be accomplished at a pace which rivals the development of chemical synthetic methods, with the ability to achieve turnovers that are two orders of magnitude (over 400-fold) greater than that of known chiral catalysts for the same class of transformation. This tunable method for manipulating boron in cells opens a whole new world of boron chemistry in living systems.
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影响因子：
15
作者：
Halo TL;Appelbaum J;Hobert EM;Balkin DM;Schepartz A
通讯作者：
Schepartz A
细胞色素 c 的定向进化促进碳-硅键形成：赋予硅生命。
DOI：
10.1126/science.aah6219
发表时间：
2016-11-25
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Kan SB;Lewis RD;Chen K;Arnold FH
通讯作者：
Arnold FH
影响因子：
16.6
作者：
Argintaru, O. Andreea;Ryu, DaWeon;Aron, Ioana;Molander, Gary A.
通讯作者：
Molander, Gary A.
影响因子：
21.8
作者：
Prier CK;Zhang RK;Buller AR;Brinkmann-Chen S;Arnold FH
通讯作者：
Arnold FH
DOI：
10.1073/pnas.1213892110
发表时间：
2013-01-22
影响因子：
11.1
作者：
Elshahawi, Sherif I.;Trindade-Silva, Amaro E.;Haygood, Margo G.
通讯作者：
Haygood, Margo G.