CAREER: Linking Structure, Stability and Protection in Protamine Packaged DNA

精细胞核中的染色质（染色体的物质）比其他细胞核中的染色质更紧密，组织更严密。这种高度的压缩，是由DNA与一类称为鱼精蛋白的蛋白质的结合引起的，被认为有助于保护DNA免受损伤。尽管以前的研究，通过鱼精蛋白紧密包装DNA的机制仍然知之甚少。 该项目的目标是使用多学科的工具阵列，以建立自然利用鱼精蛋白包装，保护和储存精子细胞中的DNA的机制的基本知识。该项目涵盖分子生物学、生物化学、生物物理学和分析化学等学科。鱼精蛋白的独特性质也有希望在新的生物技术应用中创造新的DNA递送装置和生物传感器技术的发展。研究的多学科性质将为本科生和研究生研究人员创造独特的培训机会。该项目还包括化学和生物物理学教育，包括开发大规模开放式在线课程（MOOC）。将为高中教师创建暑期研讨会，以了解并积极参与改进和评估拟议的MOOC课程，以最好地满足全国教师和学生的需求。精子发生是一个独特的多步骤过程，最终导致精核中的组蛋白被鱼精蛋白取代，最终体积约为体核的1/20。由于缺乏DNA修复，成熟精子中DNA的近晶体组织对于DNA递送和遗传信息的保护至关重要。该项目的长期目标是了解鱼精蛋白-DNA复合物中物理压实、相互作用能量学和生物化学驱动力之间的联系。该项目将使用各种结构，生物物理和生物化学方法来评估鱼精蛋白-DNA结构和体外和体内自由基稳定性。这些实验将提供一个现实的模型，如何鱼精蛋白化学控制精子染色质组织和定量知识之间的联系，DNA包装和敏感性的DNA反应性氧化物种。 鱼精蛋白表现出磷酸化位点、二硫键和锌离子的组合，使其成为研究蛋白质/DNA相互作用的物理化学和结构以及致密状态下DNA结构的独特丰富的系统。这些新的方面的鱼精蛋白有潜力的合成系统中，和模型的开发和测试，在这个项目中将作出贡献，我们的理解鱼精蛋白-DNA压缩精子染色质，以及提供见解的DNA装置的生物技术开发。

Chromatin (the material of chromosomes) is much more compact and highly organized in the nucleus of sperm cells than in the nucleus of other cells. This high degree of compaction, brought about by the association of the DNA with a class of proteins called protamines, is thought to help protect the DNA from damage. Despite previous research, the mechanisms underlying the tight packaging of DNA by protamines remain poorly understood. The goals of this project are to use a multidisciplinary array of tools to establish fundamental knowledge of the mechanisms by which nature utilizes protamines to package, protect and store DNA in sperm cells. The project spans the disciplines of molecular biology, biochemistry, biophysics and analytical chemistry. The unique properties of protamines also have promise for new biotechnological applications in the creation of novel devices for DNA delivery and the development of biosensor technologies. The multidisciplinary nature of the research will create unique training opportunities for undergraduate and graduate student researchers. The project also includes education in chemistry and biophysics, including the development of massive open online courses (MOOCs). Summer workshops will be created for high school teachers to learn about and actively participate in refining and assessing the proposed MOOC courses to best meet the needs of teachers and their students nationwide.Spermiogenesis is a unique multi-step process resulting ultimately in the replacement of histones by protamines in sperm nuclei to a final volume roughly 1/20th that of a somatic nucleus. The near crystalline organization of DNA in mature sperm is crucial for both DNA delivery and the protection of genetic information due to the absence of DNA repair. The long-term goal of the project is to understand the link between physical compaction, interaction energetics and biochemical driving forces in protamine-DNA complexes. The project will use a variety of structural, biophysical and biochemical methods to evaluate protamine-DNA structure and stability to free radicals in vitro and in vivo. These experiments will provide a realistic model of how protamine chemistry controls sperm chromatin organization and quantitative knowledge of the link between DNA packaging and susceptibility of DNA to reactive oxidative species. Protamines exhibit a combination of phosphorylation sites, disulfide bonds, and zinc ions that make them a uniquely rich system to investigate the physical chemistry and structure of protein/DNA interactions and the structure of DNA in the compacted state. These novel aspects of protamine have potential for expoitation in synthetic systems, and the models developed and tested in this project will make contributions to our understanding of protamine-DNA compaction in sperm chromatin as well as providing insights for biotechnological exploitation of DNA devices.