Search for the Structural Basis of Biomacromolecular Fun

(1)。我们已经完成了L11-RNA-硫链霉菌系统的功能动力学研究，但决定不按我最初的计划进行L11-rRNA-硫链霉菌三元络合物的结构测定，因为我们的动力学研究结果似乎表明，三元和二元(L11-rRNA)络合物的结构相似。功能动力学研究的结果已经被写在提交给《分子生物学杂志》的手稿中。(2)。我们已经基本完成了3P(周期性、平面性和像素数)方法的开发，并正在用C++编程，以便与全球流行的XploR-NIH程序包接口。“3P”方法是为了找到一种更好的方法来确定结构，如RAP，它由周期性的结构元素组成，与传统的使用核磁共振数据确定结构的方法有很大的不同。其中一篇3P文章被选为《磁共振杂志》的封面。“3P”项目的最后一期手稿已经编写完成，将在重新编码为C++后提交。这一方法学的发展促进了我们对RAP的结构生物学研究，并将对未来的结构测定项目有用。RAP的结构生物学研究及其与LRP受体的相互作用是我设想如何进行结构生物学研究的一个例子。这项研究以坚持不懈的努力解决了一个棘手的结构问题，旨在回答一个基本的生物学问题，并通过多次合作进行。这个项目导致了一个新的组氨酸开关的发现，它在酸性环境中介导高尔基体中LRP受体的释放，这是参与受体成熟的一个重要过程。我们在研究过程中制作的突变体在治疗与LRP受体相关的疾病方面具有潜在的治疗应用。我们将在不久的将来申请美国专利。在RAP中发现组氨酸开关是一种伴侣蛋白，TRAIL开辟了一种新的方法来隔离LRP受体，并可能隔离其他受体，包括同一家族的LRP5和LRP6。LRP5/6的正确折叠需要另一个专门的伴侣MESD。MESD也可以以类似于RAP突变为LRP的方式隔离LRP5/6，这一假设为研究Wnt/β-catenin信号通路的结构生物学奠定了基础。展望未来，为了实现研究目标，我已经与校内外团体建立了几个关键的合作伙伴关系。其中，我们计划与纪万昌博士的团队合作，在适当的时候结晶受体或受体片段；我们计划与夏普里奥博士的团队合作，开发一种新的方法来确定大型蛋白质受体和RNA分子的结构；我们计划与Smith-Gill博士的团队合作，研究伴侣蛋白和受体之间相互作用的体外动力学和热力学。我们将继续与Dudley Strickland教授团队在受体生物化学和生物学方面进行合作。

(1). We have completed the functional dynamics study of the L11-RNA-thiostrepton system, but decided not to pursue the structural determination of the ternary complex of L11-rRNA-thiostrepton as I have originally planed, because the result of our dynamics study appears to suggest that the structures of the ternary and the binary (L11-rRNA) complexes are similar. The results of the functional dynamics study has been written in a manuscript that was submitted to Journal of Molecular Biology. (2). We have nearly completed the "3P" (periodicity, Planarity and pixels) method development, and are in the process to program it in C++ in order to interface with the world-wide popular XPLOR-NIH package. The "3P" method was born out of a need to find a better way to determine structures like RAP that consists of periodical structural elements, and represents a significant departure from the traditional way of determining the structure using NMR data. One of the "3P" articles was selected for the cover page of Journal of Magnetic Resonance. A manuscript, the final installment of the "3P" project, has been written for a submission after the completion of the re-coding into C+++. This methodology development has facilitated our structural biology study of RAP, and will be useful for projects of structure determination in the future.The structural biology study of RAP and its interaction with the LRP receptor is an example of my vision as how a structural biology study should be conducted. This study tackled a difficult structural problem with a persistent effort, was aimed at the answering a fundamental biological question and was carried out with multiple collaborations. This project led to the discovery of a novel histidine switch that mediates the release of the LRP receptor in acidic environment in the Golgi, an important process involved in the receptor maturation. The mutants that we have made during the course of the study have potential therapeutic applications in treatment of diseases involved with the LRP receptor. We will apply for a US patent in the near future. The discovery of the histidine switch in RAP, a chaperone protein, trail blazes a new way to sequester the LRP receptor, and potentially other receptors, including LRP5 and LRP6 of the same family. Correct folding of LRP5/6 requires yet another specialized chaperone MESD. MESD can also be engineered to sequester LRP5/6 in the way similar to the mutated RAP to LRP, and this hypothesis sets a starting point to study the structural biology of the Wnt/beta-catenin signaling pathway. Looking into the future, to fulfill the research goal, I have setup several key collaborations with intramural and extramural groups. Among those, we plan to crystallize receptors or receptor fragments, whenever approiate, in collaboration with Dr. Ji's group; we plan to work with Dr. Shaprio's group to develop a new method for structure determination of large protein receptors and RNAmolecules; we plan to study the kinetic and thermodynamics in vitro of the interaction between the chaperones and the receptors in collaboration with Dr. Smith-Gill's group. We will continue our on-going collaboration with Professor Dudley Strickland group in the receptor biochemistry and biology.