RUI: The Biosynthetic Incorporation and Characterization of Seleno-and Telluromethionine in Both Control and Novel Proteins

;​R o o t E n t y F K的P : @ C o m p o b j b W o r d d o c u m e n t O b j e c t P O O l K的P: K P:吗?@ A B C D E F G H F Microsoft Word 6.0文档MSWordDoc。6;​这个项目的总体目标是将含有氨基酸的不寻常的重原子结合到蛋白质中，用作衍射标签和核磁共振（NMR）探针。异常氨基酸掺入法是一种生物合成方法，在蛋白质生物合成过程中引入硒代蛋氨酸（SeMet）和碲代蛋氨酸（TeMet）代替野生型蛋氨酸。这引入了一个硒或碲原子来代替蛋氨酸中较轻的硫原子。该研究的总体长期目标是：1)开发化学定义的细菌生长方案，使SeMet和TeMet最大限度地吸收到细胞蛋白中；2)纯化、表征和结晶所得到的对照蛋白和新蛋白；3)制备这些蛋白用于x射线衍射和/或核磁共振光谱分析。碲蛋氨酸是一种被提出的原位同构替代物，可以简化大分子晶体学的相问题，简化三维结构的确定。本科学生将在适当的水平上独立地融入本课程。每个学生研究人员将认识到他们的个人研究项目如何共同实现后一个目标。阐明蛋白质的三维结构对于我们理解生物机制和靶向设计新药都是至关重要的。目前，结构测定必须克服两个众所周知的障碍，首先是蛋白质的结晶，其次是解决蛋白质晶体学中众所周知的相问题。结晶在很大程度上被认为是一门艺术，而不是科学，因此，这个P.I.关注的是后一个问题：阶段问题。在蛋白质中发现的原子太轻（缺乏足够的质量），无法进行令人满意的结构测定。本研究的目标是通过生物机制将硒代蛋氨酸或碲代蛋氨酸结合到蛋白质中，从而将两个更重的原子：硒或碲引入生物系统。这些原子比蛋白质中的典型原子（碳、氮、氧、硫和氢）要重得多。这些原子可以通过两种不同的可用技术来利用，x射线衍射和多核磁共振波谱，这两种技术都用于确定三维结构和研究酶的功能。希望在简化结构决定方面引入新的途径，这可能最终导致对生物事件的更好的原子水平理解。*** ;;@ ....()()))()() 哦+ 0 $ H l y S u m m r I f n o r m t I o n (D h R:\WWUSER\TEMPLATE\NORMAL。DOT马西娅·斯坦伯格马西娅·斯坦伯格@ " N: @ @ TP：@ v Microsoft Word 6.0 2.0；​e = e u D D D D D D D D D C p t t t t t t t t t #

; R o o t E n t r y F K `P: @ C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l K `P: K `P: ? @ A B C D E F G H F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; 9506296 Boles The overall goal of this project is the incorporation of unusual heavy atom containing amino acids into protein for use as diffraction labels and nuclear magnetic resonance (NMR) probes. The method of unusual amino acid incorporation is a biosynthetic one, where selenomethionine (SeMet) and telluromethionine (TeMet) are introduced in vivo during protein biosynthesis in place of wild type methionine. This introduces a selenium or tellurium atom in place of the lighter sulfur atom of methionine. The overall long term objectives of the research are, 1) to develop chemically defined bacterial growth protocols that allow maximal uptake of SeMet and TeMet into cellular protein, 2 ) purify, characterize and crystallize resultant control and novel proteins, and 3) prepare these proteins for analysis by x ray diffraction and/or NMR spectroscopy. Telluromethionine is a proposed in situ isomorphous replacement which may be capable of simplifying the phase problem of macromolecular crystallography simplifying three dimensional structure determinations. Undergraduate students will be independentl y integrated into this program at the appropriate level. Each student researcher will realize how their individual research project works collectively toward the latter objective. %%% Elucidation of the three dimensional structure of proteins is central to both our understanding of biological mechanisms as well as to the targeted design of new drugs. Currently, structural determinations must overcome two well known hurdles, firstly, the crystallization of a protein and secondly, solving the well known phase problem of protein crystallography. Crystallization is largely perceived as more art than science, thus, this P.I. is focusing on the latter problem: the phase problem. The atoms found in proteins are too light (lacking sufficient mass) to allow a satisfactory structural determination. It is the goal of this research to incorporate selenomethionine or telluromethionine into proteins via a biological mechanism, thus introducing two heavier atoms into the biological system: Selenium or Tellurium. These atoms are much heavier than the typical atoms found in proteins (carbon, nitrogen, oxygen, sulfur and hydrogen). These atoms can be exploited by two different available technologies, x ray diffraction and multi nuclear magnetic resonance spectroscopy, both of which are used in the determination of three dimensional structure and the study of enzyme function. It is hoped to introduce novel avenues in the simplification of structural determinations which may eventually lead to a better atomic level understanding of biological events. *** ; ; @ ....()()))()() Oh +' 0 $ H l S u m m a r y I n f o r m a t i o n ( D h R:\WWUSER\TEMPLATE\NORMAL.DOT marcia steinberg marcia steinberg @ " N: @ @ TP: @ v A Microsoft Word 6.0 2 ; e = e u D D D D D \ f D C p t t t t t t t #