Enzymes Required for the Biosynthesis of Deoxysugars Decorating Aglycone Scaffolds

智力价值：碳水化合物的生物化学重要性怎么强调都不为过，因为它们是几乎所有生理过程中的基本元素，代表着生命系统中最丰富的生物分子。除了提供代谢能量的作用外，碳水化合物还参与广泛的生物过程，包括免疫反应、细胞-细胞相互作用、受精、细胞黏附和药物疗效等。这项研究的重点是不寻常的2，3(4)，6-三脱氧己糖，它们与重要的抗生素如红霉素A、抗肿瘤药物如阿霉素或杀虫剂如多杀菌素有关。具体地说，这个项目的目的是了解参与D-福尔马胺和D-卢布利糖生物合成的酶的结构和功能。这些特殊的糖分别装饰大环内酯类或阿萨霉素苷元支架，它们之所以被选为研究对象，是因为它们含有新的官能团，并显示出截然不同的立体化学结构。用于这项研究的技术包括X射线结晶学、定点突变、酶法合成适当的核苷酸连接的糖配体和动力学分析。最终，这些研究将揭示前所未有的化学，并为机械酶学提供重要和基础的贡献。广泛的影响：之所以选择这些项目进行研究，是因为它们非常适合通过生物化学向中学生灌输化学的兴奋，这对这个国家高质量科学的继续是绝对关键的。霍尔登实验室和丹·图米先生在威斯康星州埃奇伍德校园中学的科学课程之间的积极合作已经建立起来。在该项目的第一年，埃奇伍德将从六年级、七年级和八年级中挑选六名合格的、有兴趣的学生，开始在霍尔顿实验室与一名研究生一起实习。这一比例将是三名中学生对一名研究生。每周有一天，这些学生每人将在实验室里花大约三个小时学习该项目并帮助进行研究。新的六年级学生将被选为二年级学生，而那些升入七年级和八年级的学生将继续参加该计划。这项研究的教育部分的主要好处有三个。首先，从六年级到八年级的学生将有在研究实验室从事与生物学相关的项目的实践经验。其次，参加这个项目的研究生将有机会在实验室环境中任教，因此已经走上了建立有意义和有成就感的教育生涯的轨道。最后，第三个好处是丹·图米和霍尔顿实验室都受益。Dan Toomey有教育背景知道什么是适合中学生发展的，Holden小组有科学背景来加强他的课程。这种协同效应将对生物化学和化学主题如何呈现给中学生产生巨大的影响。

Intellectual Merit: The biochemical importance of carbohydrates cannot be overstated for they are essential elements in nearly every physiological process and represent the most abundant biomolecules in living systems. Apart from their role in providing metabolic energy, carbohydrates are involved in a wide range of biological processes including the immune response, cell-cell interactions, fertilization, cell adhesion, and drug efficacy, among others. The focus of this research is on the unusual 2,3(4),6-trideoxyhexoses, which are found attached to important antibiotics such erythromycin A, antitumor agents such as adriamycin or insecticides such as spinosad. Specifically, this project is aimed at understanding the structure and function of the enzymes involved in the biosynthesis of D-forosamine and D-rubranitrose. These particular sugars decorate macrolide, or ansamycin aglycone scaffolds, respectively, and they were chosen for study because they contain novel functional groups and display strikingly different stereochemistries. Techniques to be utilized for this investigation include x-ray crystallography, site-directed mutagenesis, enzymatic synthesis of appropriate nucleotide-linked sugar ligands, and kinetic analyses. Ultimately, these investigations will reveal unprecedented chemistries and provide important and fundamental contributions to mechanistic enzymology.Broader Impacts:These projects were selected for study because they are ideally suited for instilling in middle school students the excitement of chemistry through biochemistry, which is absolutely critical for the continuation of high quality science in this country. Active collaborations between the Holden laboratory and Mr. Dan Toomey's science classes at Edgewood Campus Middle School in Wisconsin have already been established. During the first year of the project, Edgewood will select six qualified and interested students from the sixth, seventh, and eighth grades to begin an internship with a graduate student in the Holden laboratory. The ratio will be three middle school students to one graduate student. One day a week, each of these students will spend approximately three hours in the laboratory learning about the project and helping with the research. New sixth graders will be selected for the second year, while those students moving up to seventh and eighth grade will continue with the program. The primary benefits for the educational component of this research are threefold. First, students from grades six to eight will have hands on experience in a research laboratory working on biologically relevant projects. Second, the graduate students participating in this program will have the opportunity to teach in a laboratory setting and thus will already be on a trajectory toward establishing a meaningful and fulfilling career in education. Finally, the third benefit is to both Dan Toomey and the Holden laboratory. Dan Toomey has the educational background to know what is developmentally appropriate for the middle school students, and the Holden group has the scientific background to strengthen his curriculum. This synergy will have an enormous impact on how the topics of biochemistry and chemistry are presented to middle school students.