CIC biomaGUNE, Parque Tecnológico de San Sebastián, Paseo de Miramón 182, 20014 Donostia-San Sebastián, Spain.
IMDEA-Nanociencia, Campus de Cantoblanco, 28049 Madrid, Spain.
J Struct Biol. 2018 Feb;201(2):118-129. doi: 10.1016/j.jsb.2017.09.002. Epub 2017 Sep 23.
In nature, assembled protein structures offer the most complex functional structures. The understanding of the mechanisms ruling protein-protein interactions opens the door to manipulate protein assemblies in a rational way. Proteins are versatile scaffolds with great potential as tools in nanotechnology and biomedicine because of their chemical, structural, and functional versatility. Currently, bottom-up self-assembly based on biomolecular interactions of small and well-defined components, is an attractive approach to biomolecular engineering and biomaterial design. Specifically, repeat proteins are simplified systems for this purpose. In this work, we provide an overview of fundamental concepts of the design of new protein interfaces. We describe an experimental approach to form higher order architectures by a bottom-up assembly of repeated building blocks. For this purpose, we use designed consensus tetratricopeptide repeat proteins (CTPRs). CTPR arrays contain multiple identical repeats that interact through a single inter-repeat interface to form elongated superhelices. Introducing a novel interface along the CTPR superhelix allows two CTPR molecules to assemble into protein nanotubes. We apply three approaches to form protein nanotubes: electrostatic interactions, hydrophobic interactions, and π-π interactions. We isolate and characterize the stability and shape of the formed dimers and analyze the nanotube formation considering the energy of the interaction and the structure in the three different models. These studies provide insights into the design of novel protein interfaces for the control of the assembly into more complex structures, which will open the door to the rational design of nanostructures and ordered materials for many potential applications in nanotechnology.
在自然界中，组装好的蛋白质结构提供了最复杂的功能结构。对蛋白质-蛋白质相互作用机制的理解为以合理的方式操纵蛋白质组装打开了大门。蛋白质是多功能支架，由于其化学、结构和功能的多功能性，具有巨大的潜力作为纳米技术和生物医学中的工具。目前，基于小分子和定义良好的组件的生物分子相互作用的自下而上的自组装是生物分子工程和生物材料设计的一种有吸引力的方法。具体来说，重复蛋白是为此目的的简化系统。在这项工作中，我们提供了设计新蛋白质界面的基本概念概述。我们描述了一种通过重复构建块的自下而上组装形成高级结构的实验方法。为此，我们使用设计的共识四肽重复蛋白 (CTPR)。CTPR 阵列包含多个相同的重复序列，通过单个重复间界面相互作用形成长螺旋超螺旋。在 CTPR 超螺旋上引入新的界面允许两个 CTPR 分子组装成蛋白质纳米管。我们应用三种方法形成蛋白质纳米管：静电相互作用、疏水相互作用和π-π相互作用。我们分离并表征了形成的二聚体的稳定性和形状，并考虑了三种不同模型中的相互作用能和结构来分析纳米管的形成。这些研究为设计新型蛋白质界面提供了深入的了解，以控制组装成更复杂的结构，这将为纳米技术中的许多潜在应用打开合理设计纳米结构和有序材料的大门。
