Consensus tetratricopeptide repeat proteins are complex superhelical nanosprings
Consensus tetratricopeptide repeat proteins are complex superhelical nanosprings
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共有四肽重复蛋白是复杂的超螺旋纳米弹簧
DOI：
10.1101/2021.03.27.437344
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Synakewicz M
中科院分区：
文献类型：
--
作者：
Synakewicz M
串联重复蛋白质包括小的二级结构基序，其堆叠以形成具有独特机械性质的一维阵列，所述机械性质被提出来指导其细胞功能。在这里，我们使用单分子光镊来研究共识设计的tetratricopeptide repeats（CTPRs）短螺旋-转角-螺旋基序的超螺旋阵列的折叠。我们发现，CTPRs显示弹簧般的机械响应，其中个别重复经历快速的平衡波动之间的折叠和未折叠的构象。我们合理化的力响应使用伊辛模型和解剖的CTPR在机械负荷下的折叠途径，揭示了如何重复阵列的形式从中心向两端同时。引人注目的是，我们还直接观察到蛋白质的超螺旋三级结构的力信号。使用蛋白质工程，晶体学和单分子实验，我们展示了如何超螺旋几何形状可以通过仔细放置的氨基酸取代改变，并检查这些序列的变化如何影响内在的重复稳定性和重复间耦合。我们的研究结果提供了解剖和调节重复蛋白质的稳定性和动力学，这将是必不可少的研究人员了解天然重复蛋白质的功能，并利用人工重复蛋白质在纳米技术和生物医学应用。在串联重复蛋白中，小结构基序的线性排列导致形成引人注目的超分子形状。使用单分子生物物理技术和建模方法的组合，我们解剖了设计的重复蛋白质的弹簧般的性质，并展示了它的形状和力学可以通过设计来操纵。这些新的见解，这类蛋白质的生物力学和生物化学特性给了我们一个方法论的基础，从中了解重复蛋白质的生物学功能，并利用它们在纳米技术和生物医学。
Tandem-repeat proteins comprise small secondary structure motifs that stack to form one-dimensional arrays with distinctive mechanical properties that are proposed to direct their cellular functions. Here, we use single-molecule optical tweezers to study the folding of consensus-designed tetratricopeptide repeats (CTPRs) — superhelical arrays of short helix-turn-helix motifs. We find that CTPRs display a spring-like mechanical response in which individual repeats undergo rapid equilibrium fluctuations between folded and unfolded conformations. We rationalise the force response using Ising models and dissect the folding pathway of CTPRs under mechanical load, revealing how the repeat arrays form from the centre towards both termini simultaneously. Strikingly, we also directly observe the protein’s superhelical tertiary structure in the force signal. Using protein engineering, crystallography and single-molecule experiments, we show how the superhelical geometry can be altered by carefully placed amino-acid substitutions and examine how these sequence changes affect intrinsic repeat stability and inter-repeat coupling. Our findings provide the means to dissect and modulate repeat-protein stability and dynamics, which will be essential for researchers to understand the function of natural repeat proteins and to exploit artificial repeats proteins in nanotechnology and biomedical applications.Significance statementRepetition of biological building blocks is crucial to modulating and diversifying structure and function of biomolecules across all organisms. In tandem-repeat proteins, the linear arrangement of small structural motifs leads to the formation of striking supramolecular shapes. Using a combination of single-molecule biophysical techniques and modelling approaches, we dissect the spring-like nature of a designed repeat protein and demonstrate how its shape and mechanics can be manipulated by design. These novel insights into the biomechanical and biochemical characteristics of this protein class give us a methodological basis from which to understand the biological functions of repeat proteins and to exploit them in nanotechnology and biomedicine.
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影响因子：
17.1
作者：
Baclayon, Marian;van Ulsen, Peter;Wuite, Gijs J. L.
通讯作者：
Wuite, Gijs J. L.
影响因子：
2.9
作者：
Cheng, Cecilia Y.;Jarymowycz, Virginia A.;Stone, Martin J.
通讯作者：
Stone, Martin J.
串联重复蛋白家族中环延伸的上下文相关能量学
影响因子：
3.4
作者：
Albert Perez;Alan R. Lowe;E. Main;L. Itzhaki
通讯作者：
L. Itzhaki
影响因子：
5.6
作者：
Cortajarena, Aitziber L.;Lois, Gregg;Sherman, Eilon;O'Hern, Corey S.;Regan, Lynne;Haran, Gilad
通讯作者：
Haran, Gilad
影响因子：
11.4
作者：
Das, AK;Cohen, PTW;Barford, D
通讯作者：
Barford, D