Purchase of a Linear Ion Trap/Fourier Transform Mass Spectrometer

描述(由申请人提供)： 这项提案要求为LTQ FT22000型热电子(加州桑尼维尔)型混合线性离子陷阱/傅里叶变换质谱仪提供资金，该仪器配备了电喷雾电离(ESI)源、红外多光子解离(IRMPD)和电子俘获解离(ECD)。该仪器将直接惠及一群主要用户，他们都得到了美国国立卫生研究院的研究支持，而且目前都在研究中使用质谱学。许多研究人员都是NIH支持的一个或多个路线图和计划项目赠款的参与者，这些资助将质谱分析作为研究工作的一个组成部分，并提供了一种手段，以扩大受益于这些资源的研究人员的数量。这包括约翰·霍普金斯缺血和缺氧蛋白质组学中心(N01 HV28180，由NHLBI支持)和约翰·霍普金斯赖氨酸修饰网络和途径技术中心(TCNP U54 RR020839，由NIH支持)。该仪器的所有特点和能力都将被利用，这些特点和能力有别于约翰·霍普金斯大学现有仪器上的那些。在几位研究人员对赖氨酸修饰和组蛋白结构的研究中，高质量分辨率(50,000到100,000)将区分三甲基和乙酰化位置(这可能存在于不同分子上的同一位置)。ECD和IRMPD将被用来片段由SUMO化产生的非常大的分支肽结构，以及非常大的、部分消化的多肽片段，这些片段是在组蛋白和组蛋白转移酶中定位多乙酰化赖氨酸所需的。ECD对于碳水化合物、O-连接的糖肽和带负电荷的翻译后修饰(主要是磷酸化)的结构分析也是至关重要的。这里的许多研究都是蛋白质组学研究，利用蛋白质数据库从消化的多肽中识别复杂混合物中的蛋白质(以及它们的PTM)。高质量精度(1-5ppm)是提供正确识别的关键。该仪器将存放在中大西洋质谱学实验室并由其管理，由代表主要用户和合作者的四名个人操作。

DESCRIPTION (provided by applicant): This proposal requests funds for a Thermoelectron (Sunnyvale, CA) model LTQ FT22000 hybrid linear ion trap/Fourier transform mass spectrometer, equipped with an electrospray ionization (ESI) source, infrared multiphoton dissociation (IRMPD) and electron capture dissociation (ECD). The instrument would directly benefit a group of major users all of whom have NIH research support and all of whom currently use mass spectrometry in their research. Many of the investigators are participants in one or more NIH-supported roadmap and program project grants, which incorporate mass spectrometric analysis as an integral part of the research effort and provide a means for expanding the number of investigators benefiting from these resources. This includes the Johns Hopkins Center for Proteomics of Ischemia and Hypoxia (N01 HV28180, supported by NHLBI) and the Johns Hopkins Technology Center for Networks and Pathways of Lysine Modifications (TCNP U54 RR020839, supported by NIH). All of the features and capabilities of this instrument, which distinguish it from those available on current instruments at Johns Hopkins, will be utilized. In work by several investigators on lysine modifications and the structures of histones, high mass resolution (50,000 to 100,000) will distinguish trimethyl and acetylation sites (which may exist at the same site on different molecules). ECD and IRMPD will be used to fragment the very large branched peptide structures resulting from SUMOylation, as well as very large, partially digested peptide fragments needed to map polyacetylated lysines in histones and histone transferases. ECD will also be critical for the structural analysis of carbohydrates, O-linked glycopeptides and negatively charged post- translational modifications, primarily phosphorylation. Many of the studies here are proteomics studies, utilizing protein databases for identification of proteins in complex mixtures (as well as their PTMs) from their digested peptides. High mass accuracy (1-5 ppm) is key to providing correct identifications. The instrument will be housed in and managed by the Middle Atlantic Mass Spectrometry Laboratory and operated by four individuals representing the Major Users and collaborators.