Overcoming universal restrictions on metal selectivity by protein design.
Overcoming universal restrictions on metal selectivity by protein design.
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DOI：
10.1038/s41586-022-04469-8
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发表时间：
2022-03
期刊：
影响因子：
64.8
通讯作者：
中科院分区：
文献类型：
--
作者：
选择性金属配位是金属蛋白功能的核心：每种金属蛋白必须与其同源金属辅因子配对才能发挥其生物学作用。然而，仅通过三维蛋白质结构实现金属选择性是一个巨大的挑战，因为金属配位氨基酸功能性有限，而且蛋白质本质上是灵活的，阻碍了金属的空间选择。事实上，天然蛋白质的金属结合亲和力主要由金属离子的电子特性决定，并且普遍遵循欧文-威廉姆斯 (IW) 系列 (MnII<FeII<CoII<NiII<CuII>ZnII)，几乎没有例外。因此，金属蛋白绝大多数单独结合 CuII 和 ZnII，无论其活性位点及其同源金属离子的性质如何。这导致生物体进化出复杂的稳态机制和非平衡策略来实现正确的金属形态。在这里，我们报道了一种人工二聚蛋白 (AB)2，它在热力学上克服了体外和纤维素中 IW 的限制，有利于与 IW 系列中最主要的离子 CuII 相比，较低 IW 的过渡金属的结合。与通过结构预组织实现特异性的分子设计惯例相反，(AB)2 被刻意设计得具有灵活性。这种灵活性使 (AB)2 能够采用相互排斥的、金属依赖的构象状态，从而发现了结构耦合的配位位点，这些配位位点通过强制实施不利的配位几何形状来不利于 CuII 离子。除了强调灵活性作为一种有价值的蛋白质设计元素之外，我们的结果还说明了构建选择性金属螯合剂的设计原则。
Selective metal coordination is central to the functions of metalloproteins: each metalloprotein must pair with its cognate metallocofactor to fulfill its biological role. However, achieving metal selectivity solely through a three-dimensional protein structure is a great challenge, because there is a limited set of metal-coordinating amino acid functionalities and proteins are inherently flexible, impeding steric selection of metals. In fact, metal binding affinities of natural proteins are primarily dictated by the electronic properties of metal ions and universally follow the Irving-Williams (IW) series (MnII<FeII<CoII<NiII<CuII>ZnII) with few exceptions. Accordingly, metalloproteins overwhelmingly bind CuII and ZnII in isolation, regardless of the nature of their active sites and their cognate metal ions. This led organisms to evolve complex homeostatic machinery and non-equilibrium strategies to achieve correct metal speciation. Here, we report an artificial dimeric protein, (AB)2, that thermodynamically overcomes the IW restrictions in vitro and cellulo, favoring binding of lower-IW transition metals over CuII, the most dominant ion in the IW series. Counter to the convention in molecular design to achieve specificity through structural preorganization, (AB)2 was deliberately designed to be flexible. This flexibility enabled (AB)2 to adopt mutually exclusive, metal-dependent conformational states, leading to the discovery of structurally coupled coordination sites that disfavor CuII ions by enforcing an unfavorable coordination geometry. Aside from highlighting flexibility as a valuable protein design element, our results illustrate design principles for constructing selective metal sequestration agents.
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影响因子：
--
作者：
Bailey, J. B.;Subramanian, R. H.;Churchfield, L. A.;Tezcan, F. A.
通讯作者：
Tezcan, F. A.
影响因子：
3.9
作者：
BYRD, J;WINGE, DR
通讯作者：
WINGE, DR
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
15
作者：
Brodin JD;Medina-Morales A;Ni T;Salgado EN;Ambroggio XI;Tezcan FA
通讯作者：
Tezcan FA
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD