De novo design of mercury-binding two- and three-helical bundles
De novo design of mercury-binding two- and three-helical bundles
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DOI：
10.1021/ja964351i
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发表时间：
1997-07-02
影响因子：
15
通讯作者：
Pecoraro, VL
中科院分区：
文献类型：
--
作者：
Dieckmann, GR;McRorie, DK;Pecoraro, VL
理解金属蛋白质结构的基础是金属的几何偏好与固有蛋白质结构的相对重要性。研究金属和蛋白质构象之间相互作用的一种方法是将金属结合位点引入de noVo设计的肽结构中。设计的金属肽的使用有几个潜在的优势，小分子模型。首先，肽可以被设计为在溶液中呈现明确的三级结构，从而提供了一个分子支架，其中可以引入生物学相关的金属结合残基。其次，肽的二级/三级结构可用于产生扭曲的配位环境，这在自发组装的小模型复合物中通常难以实现。第三，金属肽可以被设计成水溶性的，迄今为止很少有从头设计的金属肽的报道。1我们设计金属肽的方法是将金属结合位点引入R-螺旋卷曲螺旋的疏水内部，这是一种在许多天然蛋白质2和设计肽中发现的折叠基序。3每个配体由不同的R-螺旋提供，并且螺旋不是共价连接的。通过这种设计，我们可以利用肽的非共价自组装来控制金属的配位环境。更重要的是，通过在束的内部构建结合位点，可以控制与金属的溶剂和缓冲液连接，从而允许制备在水溶液中难以获得的金属配位环境。
Fundamental to the understanding of metalloprotein structure is the relative importance of the metal’s geometric preference vs the inherent protein structure. One approach to studying the interplay between metal and protein conformation is to introduce metal-binding sites into de noVo designed peptide structures. The use of designed metallopeptides has several potential advantages over small molecule models. First, the peptides can be designed to assume well-defined tertiary structures in solution, thus providing a molecular scaffolding into which biologically relevant metal-binding residues can be introduced. Second, the secondary/tertiary structures of the peptides can be utilized to generate distorted coordination environments which are often difficult to achieve in spontaneously-assembled small model complexes. Third, metallopeptides can be designed to be water soluble.Few de noVo designed metallopeptides have been reported to date. 1 Our approach to metallopeptide design has been to introduce a metal-binding site into the hydrophobic interior of an R-helical coiled coil, a folding motif found in many natural proteins2 and designed peptides. 3 Each ligand is donated by a different R-helix, and the helices are not covalently connected. With this design, we can utilize the noncovalent self-assembly of the peptides to control the coordination environment of the metal. More importantly, by building the binding site in the interior of the bundle, solvent and buffer ligation to the metal can be controlled, thus allowing for the preparation of metalcoordination environments that are difficult to obtain in aqueous solution.