Modulation of Coiled-Coil Dimer Stability through Surface Residues while Preserving Pairing Specificity
Modulation of Coiled-Coil Dimer Stability through Surface Residues while Preserving Pairing Specificity
复制标题
DOI：
10.1021/jacs.7b01690
复制
发表时间：
2017-06-21
影响因子：
15
通讯作者：
Jerala, Roman
中科院分区：
文献类型：
--
作者：
Drobnak, Igor;Gradisar, Helena;Jerala, Roman
卷曲螺旋二聚体是广泛存在的蛋白质结构基序，并且由于其可设计性，代表了用于组装模块化纳米结构的有吸引力的构建块。卷曲螺旋二聚体配对的特异性主要基于七肽重复的位置a、d、e和g处的残基之间的疏水和静电相互作用。另一方面，结合亲和力也可能受到背离二聚化界面的表面残基的影响。在这里，我们展示了如何设计的相互作用肽的局部螺旋倾向可以用来调整卷曲螺旋二聚体的稳定性在很宽的范围内。通过设计分子内电荷对，高局部螺旋倾向的区域可以被工程化以形成触发序列，并且在不改变肽长度或任何直接相互作用的残基的情况下调节二聚体稳定性。这一一般原理通过热稳定性的变化超过30摄氏度来证明，这是由于结合界面外仅有两个突变的结果。相同的方法被成功地用于调节一组正交卷曲螺旋的稳定性，而不影响它们的结合偏好。局部螺旋倾向和肽电荷的稳定性影响很好地描述了一个简单的线性模型，这将有助于改善目前的卷曲螺旋稳定性预测算法。我们的研究结果使得调整基于螺旋线圈的建筑模块的稳定性能够匹配合成生物学和纳米材料中的各种应用。
The coiled-coil dimer is a widespread protein structural motif and, due to its designability, represents an attractive building block for assembling modular nanostructures. The specificity of coiled-coil dimer pairing is mainly based on hydrophobic and electrostatic interactions between residues at positions a, d, e, and g of the heptad repeat. Binding affinity, on the other hand, can also be affected by surface residues that face away from the dimerization interface. Here we show how design of the local helical propensity of interacting peptides can be used to tune the stabilities of coiled-coil dimers over a wide range. By designing intramolecular charge pairs, regions of high local helical propensity can be engineered to form trigger sequences, and dimer stability is adjusted without changing the peptide length or any of the directly interacting residues. This general principle is demonstrated by a change in thermal stability by more than 30 degrees C as a result of only two mutations outside the binding interface. The same approach was successfully used to modulate the stabilities in an orthogonal set of coiled coils without affecting their binding preferences. The stability effects of local helical propensity and peptide charge are well described by a simple linear model, which should help improve current coiled-coil stability prediction algorithms. Our findings enable tuning the stabilities of coiled-coil-based building modules match a diverse range of applications in synthetic biology and nanomaterials.