Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0356, USA.
Inorg Chem. 2010 Aug 2;49(15):7106-15. doi: 10.1021/ic100926g.
We report here the construction of phenanthroline (Phen) and terpyridine (Terpy)-based hybrid coordination motifs (HCMs), which were installed on the surface of the four-helical bundle hemeprotein cytochrome cb(562). The resulting constructs, termed HPhen1, HPhen2, HPhen3, and HTerpy1, feature HCMs that are composed of a histidine ligand and a Phen or Terpy functionality located two helix turns away, yielding stable tri- or tetradentate coordination platforms. Our characterization of the tridentate HCMs indicates that they accommodate many divalent metal ions (Co(2+), Ni(2+), Cu(2+), Zn(2+)) with nanomolar to femtomolar affinities, lead to significant stabilization of the alpha-helical protein scaffold through metal-mediated cross-linking, assert tight control over protein dimerization, and provide stable and high-affinity binding sites for substitution-inert metal probes. Our analyses suggest that such tridentate HCMs may be used modularly on any alpha-helical protein surface in a sequence-independent fashion.
我们在此报告了基于菲咯啉（Phen）和三吡啶（Terpy）的杂化配位基序（HCM）的构建，这些基序被安装在四螺旋束血红素蛋白细胞色素 cb(562)的表面。所得的构建体，称为 HPhen1、HPhen2、HPhen3 和 HTerpy1，具有由组氨酸配体和位于两个螺旋转弯处的 Phen 或 Terpy 官能团组成的 HCM，产生稳定的三齿或四齿配位平台。我们对三齿 HCM 的表征表明，它们可以容纳许多二价金属离子（Co(2+)、Ni(2+)、Cu(2+)、Zn(2+)），具有纳摩尔到飞摩尔的亲和力，通过金属介导的交联显著稳定α-螺旋蛋白质支架，对蛋白质二聚化进行严格控制，并为取代惰性金属探针提供稳定且高亲和力的结合位点。我们的分析表明，这种三齿 HCM 可以以序列无关的方式在任何α-螺旋蛋白质表面上以模块化方式使用。
