Molecular underpinnings of elasticity and adhesion in self-assembling protein biopolymers

自组装蛋白质生物聚合物弹性和粘附的分子基础

• 批准号: RGPIN-2018-06146
• 负责人: Sharpe, Simon
• 金额: $ 5.25万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744144
• 关键词: Molecular; underpinnings; elasticity; adhesion; self

The self-assembly of proteins and peptides is critical to many aspects of biology. Of increasing interest are large macromolecular assemblies that form in response to local solution conditions, such as protein-rich droplets (eg. tropoelastin, RNA binding proteins in membraneless organelles, mussel foot proteins), fibrous assemblies (eg. amyloid fibrils, silk, collagen), and disordered cross-linked materials (eg. elastin, resilin). The formation and function of each assemblage underlies fundamental biological processes, and also represents an opportunity to develop novel biomaterials with controlled assembly, functionality, and physical properties. To make full use of these systems it is first important to understand the principles that drive their assembly and structure, and which define their functional properties. We have used nuclear magnetic resonance (NMR) and extensive biophysical methods to elucidate the structures and assembly mechanisms of several types of self-assembling polypeptides: amyloid fibrils and cytotoxic oligomers; transmembrane helices; fluid droplets; and crosslinked materials based on human elastin. This has provided us with a robust set of tools for tracking the structure and dynamics of self-assembling peptides through their entire assembly process. Building on these previous studies, we will determine the molecular basis for the assembly and material properties of polypeptides exhibiting two specific properties of interest elasticity and surface adhesion. i. Determine the atomistic structures of resilin and resilin-based polypeptides. Resilin is an insect elastomer that differs significantly from vertebrate elastin in sequence (more polar and aromatic) and material properties (higher compressibility), and is poorly characterized at the molecular level. Structural characterization will provide insight into how resilin performs biomechanical functions in insects, and will be used to design resilin-based peptides with defined mechanical properties. ii. Determine the molecular basis for self-assembly and surface adhesion of mussel foot proteins. Mussel foot proteins (Mfps) are repetitive, disordered and highly chemically modified proteins which self-assemble to form strong underwater adhesives of unknown structure. We will determine the molecular basis for Mfp assembly and adhesion, and will test the utility of Mfps for surface attachment of elastic biomaterials. iii. Develop a molecular understanding of compression versus extension in protein elastomers. Using NMR methods we recently developed to monitor the molecular effects of elastic extension or compression on biopolymers, we will determine how resilin-based materials, which exhibit similar elastic moduli under both extension and compression, function as elastomers. This will provide important insights for both elastic tissue biology and biomaterials design.

蛋白质和肽的自组装对于生物学的许多方面至关重要。感兴趣越来越大的是响应局部溶液条件形成的大型大分子组合，例如富含蛋白质的液滴（例如，膜无膜细胞器中的tropoelastin，RNA结合蛋白，贻贝足蛋白），纤维组件，纤维化组合物（例如，淀粉样蛋白，纤维化原纤维，胶原，胶原，胶原）和无序的材料（REGIL）。每个组合的形成和功能是基本生物学过程的基础，并且也代表了开发具有控制组装，功能和物理特性的新型生物材料的机会。为了充分利用这些系统，首先要了解推动其组装和结构并定义其功能属性的原理。我们已经使用了核磁共振（NMR）和广泛的生物物理方法来阐明几种自组装多肽的结构和组装机制：淀粉样蛋白原纤维和细胞毒性低聚物；跨膜螺旋；液滴；和基于人类弹性蛋白的交联材料。这为我们提供了一套强大的工具，用于通过整个组装过程跟踪自组装肽的结构和动态。在这些先前的研究的基础上，我们将确定具有两种特定的感兴趣弹性和表面粘附特性的多肽的组装和材料特性的分子基础。 我。确定基于溶质蛋白和依赖蛋白的多肽的原子结构。 Resilin是一种昆虫弹性体，其序列（更极性和芳香族性）和材料特性（较高的可压缩性）与脊椎动物弹性蛋白有显着差异，并且在分子水平上的特征很差。结构表征将提供有关Resilin如何在昆虫中执行生物力学功能的洞察力，并将用于设计具有定义的机械性能的基于Resilin的肽。 ii。确定贻贝脚蛋白的自组装和表面粘附的分子基础。贻贝脚蛋白（MFP）是重复的，无序且高度化学修饰的蛋白质，自组装以形成结构未知结构的坚固的水下粘合剂。我们将确定MFP组装和粘附的分子基础，并将测试MFPS对弹性生物材料表面附着的效用。 iii。在蛋白质弹性体中对压缩与扩展的分子理解。使用NMR方法，我们最近开发了用于监测弹性延伸或压缩对生物聚合物的分子效应，我们将确定在扩展和压缩下表现出相似的弹性模量的基于溶质蛋白的材料，作为弹性体的作用。这将为弹性组织生物学和生物材料设计提供重要见解。