Biomolecular Characterization via Radical Directed Dissociation

加州大学河滨分校的Ryan R.Julian教授得到了化学部的化学测量和成像(CMI)计划以及生物科学局的生物研究仪器开发(IDBR)计划的支持，以进一步开发他的质谱学方法，这些方法最初是为了鉴定和表征多肽和蛋白质而开发的。该项目将扩大可用于质谱学的生物分子的范围，为分子生物学、生物化学和医学等多个领域的科学研究开辟新的途径。具体地说，所提出的改进寡糖分析的方法注定会广泛使用，因为这些都是生物和生物医学上重要的分子，现有的工具对这些分子只能起到适度的作用。在这种情况下，该项目承诺加强我们对生命过程的理解。在进行这项研究的过程中，研究生和本科生将在生物分析技术、质谱学和化学合成方面获得宝贵的技能。PI将积极参与UCR项目(GradEDge和AGEP)，这些项目侧重于研究生院内少数族裔学生的成功进步，研究团队将参加当地K-12学校的科学博览会和科学演示。该项目有三个具体目标：(1)探索自由基定向解离(RDD)用于阐明寡糖结构的用途，并描绘RDD在寡糖中产生的独特裂解途径。这一目标的重点将放在一系列靶标上，包括糖胺多糖、O-和N-连接的糖聚糖和糖肽；(2)使用RDD识别抗氧化肽并确定其溶液相抗氧化能力。将研究生物相关蛋白质的内在抗氧化能力和影响抗氧化能力的因素，并将结合序列替换和MS/MS实验来揭示自由基是如何被隔离的信息；以及(3)利用光笼共价标记和光化学来绘制蛋白质，特别是多蛋白质复合体的高阶溶液相结构。

Professor Ryan R. Julian of the University of California Riverside is supported by the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry and the Instrument Development for Biological Research (IDBR) Program in the Directorate for Biological Sciences to further develop his mass spectrometry methodologies, which were initially developed for the identification and characterization of peptides and proteins. The project will expand the scope of biomolecules to which mass spectrometry can be applied, opening up new avenues of scientific research in numerous fields including molecular biology, biochemistry and medicine. Specifically, the proposed methods for improved oligosaccharide analysis are destined to be broadly useful as these are biologically and biomedically important molecules for which existing tools are only moderately useful. In this context, the project promises to enhance our understanding of life processes. In the course of conducting this research, graduate and undergraduate students will acquire valuable skills in bioanalytical technologies, mass spectrometry and chemical synthesis. The PI will actively participate in UCR programs (GradEDge and AGEP) that are focused on the successful advancement of minority students within the graduate school, and the research team will participate in science fairs and science demonstrations at local K-12 schoolsThe project is organized in three specific objectives: (1) to explore the utility of radical directed dissociation (RDD) for the elucidation of the structure of oligosaccharides and to delineate the unique fragmentation pathways that RDD produce in oligosaccharides. The focus of this objective will be on a range of targets including glycosaminoglycans, O- and N- linked glycans and glycopeptides; (2) to use RDD to identify antioxidant peptides and determine their solution phase antioxidant capacity. The inherent antioxidant capacity of biologically relevant proteins and the factors that influence antioxidant capacity will be investigated, and a combination of sequence substitution and MS/MS experiments will be used to reveal information about how radicals are sequestered; and (3) to utilize photocaged covalent labels and photochemistry to map the higher order solution phase structure of proteins, in particular multiprotein complexes.