Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan.
J Pept Sci. 2019 Apr;25(4):e3158. doi: 10.1002/psc.3158. Epub 2019 Feb 19.
Redox-active ruthenium complexes have been widely used in various fields; however, the harsh conditions required for their synthesis are not always conducive to their subsequent use in biological applications. In this study, we demonstrate the spontaneous formation of a derivative of tris(bipyridine)ruthenium at 37°C through the coordination of three bipyridyl ligands incorporated into a peptide to a ruthenium ion. Specifically, we synthesized six bipyridyl-functionalized peptides with randomly chosen sequences. The six peptides bound to ruthenium ions and exhibited similar spectroscopic and electrochemical features to tris(bipyridine)ruthenium, indicating the formation of ruthenium complexes as we anticipated. The photo-excited triplet state of the ruthenium complex formed in the peptides exhibited an approximately 1.6-fold longer lifetime than that of tris(bipyridine)ruthenium. We also found that the photo-excited state of the ruthenium complexes was able to transfer an electron to methyl viologen, indicating that the ruthenium complexes formed in the peptides had the same ability to transfer charge as tris(bipyridine)ruthenium. We believe that this strategy of producing ruthenium complexes in peptides under mild conditions will pave the way for developing new metallopeptides and metalloproteins containing functional metal-complexes.
氧化还原活性钌配合物在各个领域得到了广泛应用；然而，其合成所需的苛刻条件并不总是有利于它们随后在生物应用中的使用。在本研究中，我们通过将三个整合到肽中的双吡啶配体与钌离子配位，在 37°C 下证明了三（联吡啶）钌的衍生物的自发形成。具体来说，我们合成了六个具有随机序列的双吡啶功能化肽。这六个肽与钌离子结合，并表现出与三（联吡啶）钌相似的光谱和电化学特征，表明形成了我们预期的钌配合物。在肽中形成的钌配合物的光激发三重态的寿命比三（联吡啶）钌长约 1.6 倍。我们还发现，钌配合物的光激发态能够将电子转移到甲基紫精，表明在肽中形成的钌配合物具有与三（联吡啶）钌相同的电荷转移能力。我们相信，这种在温和条件下在肽中生产钌配合物的策略将为开发含有功能金属配合物的新型金属肽和金属蛋白铺平道路。
