Acquisition of a linear Q-Trap LC/MS/MS System

描述（由申请人提供）：购买线性Q-Trap LC/MS/MS系统：研究资源部申请资金用于购买Applied Biosystems Q-Trap Pro LC/MS/MS系统。在此仪器开发之前，三维离子阱是蛋白质组学研究的全部可用工具。尽管三维离子阱非常有用，但它们在蛋白质组学研究中存在一些缺点。质量精度较差，有时会导致数据库搜索结果不明确。在典型的质谱/质谱实验中没有观察到重要的低质量离子。可以通过使用更长的循环时间来提高分辨率。然而，这将导致灵敏度的显著降低。最后，真正的前体离子和中性损失扫描，这是有用的蛋白质表征，是不可用的。与传统的3-D离子阱和标准的三重四极杆质谱仪相比，线性（或2维）离子阱具有更高的分辨率和质量精度，这为数据库搜索结果提供了更大的信心。此外，在MS和MS/MS模式下，优越的全扫描灵敏度允许分析重要的低拷贝蛋白。Q-Trap仪器提供标准的三重四极柱样MS/MS碎片模式，没有低质量截止。这提供了更好的肽序列覆盖，因此也提高了数据库搜索。与传统的三维离子阱相比，线性q阱系统具有独特的扫描功能。这允许在单次LC/MS运行期间进行一系列复杂的MS/MS实验（例如前体离子和恒定中性损失扫描），因此在进行蛋白质鉴定实验时显着提高了吞吐量。增强型多电荷（EMC）扫描特别有用，因为它消除了大多数单电荷离子，这反过来又最大化了多电荷离子的信噪比。由四个nih资助的研究人员组成的主要用户组将使用该仪器进行蛋白质组学研究。一个由6名美国国立卫生研究院资助的研究人员组成的小用户组也将使用该仪器进行蛋白质组学研究。由8名美国国立卫生研究院资助的研究人员组成的偶尔用户组将在仪器剩余时间的大部分时间内使用该仪器。据估计，在五年内，该仪器将使另外20-30名研究人员的研究项目受益。因此，这台新仪器将对美国国立卫生研究院资助的38-48名宾夕法尼亚大学研究人员的研究项目产生重大影响。

DESCRIPTION (provided by applicant): Acquisition of a linear Q-Trap LC/MS/MS System: Funds are requested from the Division of Research Resources for the purchase of an Applied Biosystems Q-Trap Pro LC/MS/MS system. Until the development of this instrument, 3-Dimensional (3-D) ion traps were all that have been available for proteomics research. Although 3-D ion traps have been extremely useful, they suffer form several disadvantages for proteomics research. Mass accuracy is poor, which sometimes results in ambiguous database search results. Important low mass ions are not observed in typical MS/MS experiments. It is possible to increase resolution by using longer cycle times. However, this results in a significant decrease in sensitivity. Finally, true precursor ion and neutral loss scans, which are useful for protein characterization, are not available. The linear (or 2- Dimensional) ion trap has enhanced resolution and mass accuracy compared to conventional 3-D ion trap and standard triple quadrupole mass spectrometers, which provides greater confidence in database search results. Furthermore, superior full-scan sensitivity in MS and MS/MS modes permits analysis of important low-copy proteins. The Q-Trap instrument provides standard triple quadrupole-like MS/MS fragmentation patterns with no low mass cutoff. This provides better peptide sequence coverage, and so also improves database searching. Unique scan functions are also available on the linear Q-Trap system when compared with the conventional 3- D ion trap. This allows a series of sophisticated MS/MS experiments (such as precursor ion and constant neutral loss scans) to be conducted during a single LC/MS run and so significantly enhances throughput when conducting protein identification experiments. The Enhanced Multiply Charged (EMC) scan is particularly useful as it eliminates the majority of singly charged ions, which in turn, maximizes the signal-to-noise ratio for multiply charged ions. A major user group consisting of four NIH-funded investigators would use the instrument to perform proteomics research. A minor user group consisting of six NIH-funded investigators would also conduct proteomics research using the instrument. An occasional user group of eight NIH-funded investigators would use the instrument for most of the remaining instrument time. It is estimated that over five years, the instrument would benefit the research programs of an additional 20-30 investigators. Therefore, the new instrument would impact significantly on research programs of some 38-48 NIH-funded investigators at the University of Pennsylvania.