Mg2+-Dependent High Mechanical Anisotropy of Three-Way-Junction pRNA as Revealed by Single-Molecule Force Spectroscopy
Mg2+-Dependent High Mechanical Anisotropy of Three-Way-Junction pRNA as Revealed by Single-Molecule Force Spectroscopy
复制标题
单分子力谱揭示三路连接 pRNA 的 Mg2 依赖性高机械各向异性
DOI：
10.1002/anie.201704113
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Cao Yi
中科院分区：
文献类型：
--
作者：
Sun Yang;Di Weishuai;Li Yiran;Huang Wenmao;Wang Xin;Qin Meng;Wang Wei;Cao Yi
力学各向异性在生物组织中普遍存在，但在合成生物材料中很难再现。开发具有各向异性力学响应的分子积木是实现各向异性生物材料工程化的关键。来源于DNA包装马达的三向连接（3 WJ）pRNA在Mg 2+结合时显示出强的机械各向异性。在不存在Mg 2+的情况下，3 WJ-pRNA的机械强度较弱，没有明显的机械各向异性。在Mg 2+的存在下，解折叠力可沿不同的牵拉方向相差沿着超过4倍，范围为约47 pN至约219 pN。 3 WJ-pRNA的力学各向异性源于两个Mg 2+结合位点断裂的拉伸方向依赖性协同性，这是生物大分子力学各向异性的一种新机制。预计3 WJ-pRNA可用作构建具有可控机械各向异性的生物材料的关键要素。
Mechanical anisotropy is ubiquitous in biological tissues but is hard to reproduce in synthetic biomaterials. Developing molecular building blocks with anisotropic mechanical response is the key towards engineering anisotropic biomaterials. The three‐way‐junction (3WJ) pRNA, derived fromϕ29 DNA packaging motor, shows strong mechanical anisotropy upon Mg2+binding. In the absence of Mg2+, 3WJ‐pRNA is mechanically weak without noticeable mechanical anisotropy. In the presence of Mg2+, the unfolding forces can differ by more than 4‐fold along different pulling directions, ranging from about 47 pN to about 219 pN. Mechanical anisotropy of 3WJ‐pRNA stems from pulling direction dependent cooperativity for the rupture of two Mg2+binding sites, which is a novel mechanism for the mechanical anisotropy of biomacromolecules. It is anticipated that 3WJ‐pRNA can be used as a key element for the construction of biomaterials with controllable mechanical anisotropy.