Collaborative Research: Unique Structural Proteins and Cross-linking Reactions that Control Physical Properties of Insect Exoskeletons

昆虫的外骨骼既是皮肤又是支撑骨架。它是由一种叫做角质层的物质形成的，角质层由蛋白质和碳水化合物（几丁质）以及被称为儿茶酚的简单有机化合物组成。尽管这种有限的成分调色板，角质层具有显著不同的性质，从柔软和灵活到坚硬和刚性。它很结实，但与脊椎动物的骨头相比却很轻，因为角质层缺乏矿物质成分。昆虫外骨骼的机械特性无疑有助于昆虫在适应几乎所有栖息地和发展飞行能力方面取得压倒性的成功。本提案描述了研究生物化学化合物和化学反应形成昆虫角质层的实验，并了解这些如何导致角质层区域具有不同的机械性能。本跨学科项目涉及生物化学家和工程师，利用红粉甲虫（Tribolium castaneum）作为模式生物来研究角质层蛋白质特性和化学与刚性角质层发育的关系。所提出的方法结合分子和力学分析，在角质层生物化学的基本理解和基于角质层化学的潜在有用的新材料的开发方面取得进展。这项研究产生的更广泛的影响将包括对本科生和研究生的教育和培训。扩大科学参与机会的具体努力将包括让不同的本科生获得研究经验，并向初中生和高中生推广。对昆虫这一关键生理系统的理解的进展将导致对昆虫生物学的更深入的了解，这将有助于生产基于角质层化学的新型交联生物聚合物。这种新型“生物启发”材料在医学、制药和农业方面具有潜在的技术应用。

The exoskeleton of insects functions as both skin and supporting skeleton. It is formed from a material called cuticle, composed of proteins and a carbohydrate (chitin), and simple organic compounds known as catechols. Despite this limited compositional palette, cuticle has remarkably diverse properties, ranging from soft and flexible to hard and rigid. It is quite strong, but it is lightweight compared with bone of vertebrate animals, because cuticle lacks mineral components. The mechanical properties of insect exoskeleton have certainly contributed to the overwhelming success of insects in adapting to nearly every habitat and in their development of the ability to fly. This proposal describes experiments to investigate the biochemical compounds and chemical reactions that form insect cuticle and to understand how these result in cuticular regions with differing mechanical properties. This interdisciplinary project, involving biochemists and engineers, makes use of the red flour beetle, Tribolium castaneum, as a model organism to investigate the relationships of cuticle protein properties and chemistry with the development of rigid cuticle. The proposed approaches combine molecular and mechanical analysis to yield advances in fundamental understanding of cuticle biochemistry and development of potentially useful new materials based on cuticle chemistry. Broader impacts resulting from the research will include education and training for undergraduate and graduate students. Specific efforts at broadening opportunities for participation in science will include research experiences by diverse undergraduate students and outreach to middle school and high school students. Advances in understanding of this critical physiological system in insects will lead to a deeper knowledge of insect biology will aid in producing new types of cross-linked biopolymers based on the chemistry of cuticle. This new class of 'bioinspired' materials has potential technological applications in medicine, pharmacy and agriculture.