2-Benzoylpyridine Ligand Complexation with Gold Critical for Propargyl Ester-Based Protein Labeling
2-Benzoylpyridine Ligand Complexation with Gold Critical for Propargyl Ester-Based Protein Labeling
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DOI：
10.1002/chem.201802058
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发表时间：
2018-07-25
影响因子：
4.3
通讯作者：
Tanaka, Katsunori
中科院分区：
文献类型：
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作者：
Lin, Yixuan;Vong, Kenward;Tanaka, Katsunori
在以前报道的工作中，Au-III配合物与2-苯甲酰基吡啶配体，BPy-Au，被prebind到蛋白质，并用于发现一种新的蛋白质定向标记方法与炔丙基酯官能团。在这项工作中，进一步的研究发现，没有2-苯甲酰基吡啶配体的金催化剂（例如，NaAuCl 4）具有显著降低的蛋白质标记水平。然后，机理研究表明，BPy-Au和炔丙基酯经历了一个罕见的C（sp（2））-C（sp）芳基-炔基交叉偶联的例子，可能是通过自发还原消除。总的来说，这些观察似乎表明，BPy-Au介导的，炔丙基酯为基础的蛋白质标记通过活化酯中间体，这有助于我们理解这个过程，并将有助于扩大/优化金催化剂的使用在未来的生物缀合应用，特别是在体内。
In previously reported work, Au-III complexes co-ordinated with 2-benzoylpyridine ligand, BPy-Au, were prebound to a protein and used to discover a novel protein-directed labeling approach with propargyl ester functional groups. In this work, further examination discovered that gold catalysts devoid of the 2-benzoylpyridine ligand (e.g., NaAuCl4) had significantly reduced levels of protein labeling. Mechanistic investigations then revealed that BPy-Au and propargyl esters undergo a rare example of C(sp(2))-C(sp) aryl-alkynyl cross-coupling, likely through spontaneous reductive elimination. Overall, these observations appear to suggest that BPy-Au-mediated, propargyl ester-based protein labeling acts via an activated ester intermediate, which contributes to our understanding of this process and will aid the expansion/optimization of gold-catalyst usage in future bioconjugation applications, especially in vivo.