School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
Centre for Membrane Interactions and Dynamics, and Krebs Institute, Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
Dalton Trans. 2018 Aug 21;47(31):10784-10790. doi: 10.1039/c8dt01568f. Epub 2018 Jul 19.
Herein the first example of a bimetallic coiled coil featuring a lanthanide binding site is reported, opening opportunities to exploit the attractive NMR and photophysical properties of the lanthanides in multi metallo protein design. In our efforts to fully characterise the system we identified for the first time that lanthanide binding to such sites is pH dependent, with optimal binding at neutral pH, and that the double AsnAsp site is more versatile in this regard than the single Asp site. Our second site featured the structural HgCys site, the chemistry of which was essentially unaltered by the presence of the lanthanide site. In fact, both metal binding sites within the hetero bimetallic coiled coil displayed the same properties as their mononuclear single binding site controls, and operated independently of each other. Finally, pH can be used as an external trigger to control the binding of Hg(ii) and Tb(iii) to the two distinct sites within this coiled coil, and offers the opportunity to "activate" metal binding sites within complex multi metallo and multi-functional designs.
本文首次报道了一种具有镧系元素结合位点的双金属螺旋线圈，为在多金属蛋白设计中利用镧系元素的诱人 NMR 和光物理性质开辟了机会。在我们努力充分表征该系统的过程中，我们首次发现，此类位点与镧系元素的结合依赖于 pH 值，在中性 pH 值下具有最佳结合，并且双天冬氨酸位点比单个天冬氨酸位点在这方面更具多功能性。我们的第二个位点具有结构 HgCys 位点，其化学性质基本上不受镧系元素位点的影响。事实上，同型双金属螺旋线圈中的两个金属结合位点表现出与其单核单结合位点对照相同的性质，并且彼此独立地运作。最后，pH 值可用作外部触发因素来控制 Hg(ii)和 Tb(iii)与该螺旋线圈内两个不同位点的结合，为在复杂的多金属和多功能设计中“激活”金属结合位点提供了机会。
