Design and characterization of biofilm-inspired amyloid biomaterials.

该项目由生物材料计划和刺激竞争性研究的既定计划（EPSCoR）BMAT联合资助：生物膜启发淀粉样生物材料的设计和表征。自然产生的材料具有非凡的性能，无论是由丝素蛋白制成的高强度蜘蛛网，还是由细菌蛋白卷曲纤维制成的生物膜的坚固保护层。“淀粉样蛋白”是最坚固、最稳定的生物材料之一，它是由蛋白质的自结合形成的，这种自结合产生密集排列有序的蛋白质分子，具有高稳定性和坚固的材料特性。淀粉样蛋白独特的自组装过程、机械稳健性、热相容性和生物相容性为开发各种应用的仿生合成淀粉样材料提供了丰富的平台。然而，蛋白质氨基酸序列与淀粉样纤维材料性质之间的关系尚缺乏研究。该项目汇集了一个具有分子生物物理学、合成化学和材料科学专业知识的跨学科团队，旨在建立一系列全新肽的结构、功能、加工和特性之间的关系，这些肽旨在模拟Curli淀粉样蛋白的特定序列。对新型淀粉样蛋白材料结构-性质关系的基本理解将为生物技术和药理学应用的功能性生物材料的开发提供平台。作为该项目的一部分，研究生和本科生将在学院实验室进行研究和交叉训练。推广工作的目的是让密西西比州人口的多样性充分参与进来。密西西比州是全国最贫穷的地区之一，非洲裔美国人占总人口的比例最高。尽管淀粉样蛋白与许多疾病有关，但越来越清楚的是，它们也在细菌、真菌、昆虫、无脊椎动物和人类的细胞过程中发挥着必要的功能作用。在细菌中，蛋白质CsgA Curli形成淀粉样纤维，这是细胞外生物膜的重要组成部分，细菌菌落在其涂层下茁壮成长，逃避各种环境损害。卷曲淀粉样蛋白是结构保守的交叉β-片结构，可容纳紧密排列的相互作用，为生物膜提供坚固的材料特性。我们假设，基于CsgA序列作为模板，可以通过序列-形态-生物活性相关性设计有效的变异淀粉样蛋白抗菌材料。拟议的研究将验证这一假设，并将解决序列中氨基酸的类型和位置偏差如何与聚集体的生化，形态和机械特性相关的问题。这些将有两个具体的目标：第一个目标将集中在合理的设计，合成和肽和肽模拟物的生物物理特性，以及它们的细胞和抗微生物活性，从Curli衍生的线索。第二个目标将集中于材料的性质，如形态和纳米力学稳定性、孔隙率和形成水凝胶的能力。总之，提出的迭代方法将为设计受Curli启发的淀粉样蛋白材料奠定基础，基于序列、结构、形态和微生物活性。这将增强我们目前对基本细胞过程中新生淀粉样蛋白的理解，并促进用于制药和生物技术应用的生物材料的开发。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project is jointly funded by the Biomaterials program and the Established Program to Stimulate Competitive Research (EPSCoR)BMAT: Design and characterization of biofilm-inspired amyloid biomaterials.Non-technical abstractNature produces materials with extraordinary properties, be it high strength spiderweb made of the protein silk fibroin or robust protective coat of a biofilm by fibers of the bacterial protein Curli. One of the strongest and most stable biological materials is the ‘amyloid’, which is formed from the self-association of proteins that produces densely packed, orderly protein molecules with high stability and robust material properties. The unique self-assembly processes, mechanical robustness, thermal and biocompatibility of amyloid proteins provide a rich platform for potential exploitation of bio-inspired synthetic amyloid materials for various applications. However, the relationship between protein amino acid sequence and material properties of amyloid fibers is lacking. This project brings together an interdisciplinary team with expertise in molecular biophysics, synthetic chemistry, and materials science to establish the relationships between structure, function, processing, and properties in a series of de novo peptides designed to mimic specific sequences of Curli amyloids. The fundamental understanding of structure-property relationships in the novel amyloid materials generated will serve as a platform for the development of functional biomaterials for biotechnological and pharmacological applications. As a part of this project, graduate and undergraduate students will be engaged in the research and cross-trained in faculty laboratories. Outreach efforts will be designed to engage the full diversity of Mississippi’s population, which is among the poorest in the nation and represents the highest African American population as a percentage of total population. Technical abstractAlthough amyloids are linked to many pathologies, it is becoming abundantly clear that they also play functional roles required for cellular processes in bacteria, fungi, insects, invertebrates, and humans. In bacteria, the protein CsgA Curli forms amyloid fibers that are important components of extracellular biofilms, coatings under which bacterial colonies thrive evading various environmental insults. Curli amyloids are structurally conserved cross-β-sheet structures that accommodate tightly packed interactions to provide robust material characteristics for biofilms. We hypothesize that based on the CsgA sequence as a template, ¬¬effective variant amyloid antimicrobial materials can be designed through sequence-morphology-bioactivity correlations. The proposed research will test this hypothesis and will address the question of how type and positional biases of amino acid in the sequence correlate to biochemical, morphology, and mechanical properties of the aggregates. These will be accomplished with two specific aims: The first aim will focus on the rational design, synthesis and biophysical characterization of peptides and peptide mimics along with their cellular and anti-microbial activities from cues derived from Curli. The second aim will focus on material properties such as morphology and nanomechanical stability, porosity, and ability to form hydrogels. Together, the proposed iterative approach will lay a foundation for designing amyloid materials inspired by Curli, based on sequence, structure, morphology, and microbial activity. This will enhance our current understanding of de novo amyloids in fundamental cellular processes and facilitate the development of biomaterials for pharmaceutical and biotechnology applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.