Residue-Selective Protein C-Formylation via Sequential Difluoroalkylation-Hydrolysis.
Residue-Selective Protein C-Formylation via Sequential Difluoroalkylation-Hydrolysis.
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DOI：
10.1021/acscentsci.0c01193
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发表时间：
2021-01-27
影响因子：
18.2
通讯作者：
Davis BG
中科院分区：
文献类型：
--
作者：
Imiołek M;Isenegger PG;Ng WL;Khan A;Gouverneur V;Davis BG
羰基现在是化学生物学中广泛使用的非蛋白质原性官能团，但其在蛋白质中产生的方法依赖于带有羰基的非天然氨基酸的共翻译掺入或现有天然氨基酸的氧化转化（化学或酶促）。如果可行，通过形成C-C键的C-羰基化直接添加C=O基团的替代策略，特别是在目前难以接近的氨基酸位点，将提供一种强有力的方法来增加有价值的反应性和扩展蛋白质中的可能功能。在这里，HCF 2·产生的方法的调查，我们表明，还原性光氧化还原催化，使温和的自由基介导的二氟甲基化水解的天然蛋白质残基作为一种有效的羰基化方法。HCF 2·的固有选择性允许优先修饰Trp残基。所得的C-2-二氟甲基化Trp经历Reimer-Tiemann型脱卤作用，从而在蛋白质中提供高度有效的自发水解塌陷以形成羰基化HC（O）-Trp（C-甲酰基-Trp = CfW）残基。人们发现这种新的非天然蛋白质残基CfW不仅在生物缀合、连接和标记反应中有效，而且其吸收和荧光发射最大值显示出强烈的“红移”，允许直接使用Trp位点作为蛋白质甚至细胞中的紫外可见荧光团。以这种方式，这种用于有效产生掩蔽的甲酰基自由基“HC（0）·”等同物的方法使得能够在蛋白质中进行C-C键形成羰基化的第一个实例，从而扩展了可以选择性地和后处理地“编辑”到生物学中的化学反应性和光谱功能。自由基二氟甲基化（→C− CF2 H）和随后的水解（→C−CHO）允许直接的，色氨酸选择性引入蛋白质醛，其作为蛋白质和细胞上的标记和最小尺寸的荧光标签。
The carbonyl group is now a widely useful, nonproteinogenic functional group in chemical biology, yet methods for its generation in proteins have relied upon either cotranslational incorporation of unnatural amino acids bearing carbonyls or oxidative conversion (chemical or enzymatic) of existing natural amino acids. If available, alternative strategies for directly adding the C=O group through C–C bond-forming C-carbonylation, particularly at currently inaccessible amino acid sites, would provide a powerful method for adding valuable reactivity and expanding possible function in proteins. Here, following a survey of methods for HCF2· generation, we show that reductive photoredox catalysis enables mild radical-mediated difluoromethylation-hydrolysis of native protein residues as an effective method for carbonylation. Inherent selectivity of HCF2· allowed preferential modification of Trp residues. The resulting C-2-difluoromethylated Trp undergoes Reimer-Tiemann-type dehalogenation providing highly effective spontaneous hydrolytic collapse in proteins to carbonylated HC(O)-Trp (C-formyl-Trp = CfW) residues. This new, unnatural protein residue CfW not only was found to be effective in bioconjugation, ligation, and labeling reactions but also displayed strong “red-shifting” of its absorption and fluorescent emission maxima, allowing direct use of Trp sites as UV–visualized fluorophores in proteins and even cells. In this way, this method for the effective generation of masked formyl-radical “HC(O)·” equivalents enables first examples of C–C bond-forming carbonylation in proteins, thereby expanding the chemical reactivity and spectroscopic function that may be selectively and post-translationally “edited” into biology. Radical difluoromethylation (→C−CF2H) and subsequent hydrolysis (→C−CHO) allow direct, Trp-selective introduction of protein aldehyde, which acts as both a labeling and minimally sized fluorescent tag on proteins and cells.
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影响因子：
3.3
作者：
Ladner, Carol L.;Khai Tran;Edwards, Robert A.
通讯作者：
Edwards, Robert A.
影响因子：
64.8
作者：
BLAKE, CCF;KOENIG, DF;SARMA, VR
通讯作者：
SARMA, VR
影响因子：
64.8
作者：
Josephson, Brian;Fehl, Charlie;Davis, Benjamin G.
通讯作者：
Davis, Benjamin G.
影响因子：
3.3
作者：
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通讯作者：
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影响因子：
16.6
作者：
Noisier, Anais F. M.;Johansson, Magnus J.;Gopalakrishnan, Ranganath
通讯作者：
Gopalakrishnan, Ranganath