Hyperstable De Novo Protein with a Dimeric Bisecting Topology
Hyperstable De Novo Protein with a Dimeric Bisecting Topology
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DOI：
10.1021/acssynbio.9b00501
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发表时间：
2020-02-01
影响因子：
4.7
通讯作者：
Arai, Ryoichi
中科院分区：
文献类型：
--
作者：
Kimura, Naoya;Mochizuki, Kenji;Arai, Ryoichi
最近，我们设计并组装了一种名为WA20的分子间折叠二聚体新蛋白质的蛋白质纳米构建块(PN块)。利用这种二聚体4-螺旋束，我们构建了一系列自组装的超分子纳米结构，包括多面体和链状络合物。在这里，我们描述了通过设计稳定螺旋和疏水核心的突变来稳定WA20。重新设计的蛋白质具有显著更高的中点变性，其中最稳定的变体被称为超级WA20(SUWA)，显示出极高的中点(T-m=122摄氏度)，远远高于WA20的T-m(75摄氏度)。SUWA的晶体结构显示为分子间折叠的二聚体，具有平分的U拓扑结构，类似于亲本的WA20结构，一个原始体的两个长的α-螺旋与另一个原始体的螺旋缠绕在一起。分子动力学模拟表明，在SUWA中心重新设计的疏水核心显著抑制了在WA20相同区域观察到的螺旋的变形，这表明这是稳定SUWA结构的关键因素。这种超稳定的从头蛋白有望在新型自组装纳米结构中用作PN-Block组件的纳米级支柱。
Recently, we designed and assembled protein nanobuilding blocks (PN-Blocks) from an intermolecularly folded dimeric de novo protein called WA20. Using this dimeric 4-helix bundle, we constructed a series of self-assembling supramolecular nanostructures including polyhedra and chain-type complexes. Here we describe the stabilization of WA20 by designing mutations that stabilize the helices and hydrophobic core. The redesigned proteins denature with substantially higher midpoints, with the most stable variant, called Super WA20 (SUWA), displaying an extremely high midpoint (T-m = 122 degrees C), much higher than the T-m of WA20 (75 degrees C). The crystal structure of SUWA reveals an intermolecularly folded dimer with bisecting U topology, similar to the parental WA20 structure, with two long alpha-helices of a protomer intertwined with the helices of another protomer. Molecular dynamics simulations demonstrate that the redesigned hydrophobic core in the center of SUWA significantly suppresses the deformation of helices observed in the same region of WA20, suggesting this is a critical factor stabilizing the SUWA structure. This hyperstable de novo protein is expected to be useful as nanoscale pillars of PN-Block components in new types of self-assembling nanoarchitectures.