MASS SPECTROMETER

这是对飞行时间(TOF)质谱仪的请求。该仪器将在索尔克研究所的许多研究人员和其他学术机构的研究人员的研究项目中发挥关键作用(见支持函)。我们将获得有关新激素、毒素和生长因子的准确质量和结构信息，并表征已知一级结构的分子中翻译后修饰的位置和性质。已经确定了一个由10名调查人员组成的小组，他们的研究依赖于只能用所要求的仪器进行的分析。仪器的灵敏度对于我们目前尝试表征新的多肽和蛋白质是至关重要的。对各种不稳定多肽的结果表明，与连续提取和目前可用的更基本的分析相比，脉冲离子提取和所需仪器上的激光光学系统具有更高的灵敏度。该仪器对于确定磷蛋白中的磷酸化位置也是至关重要的，在那里，低水平的磷酸化或引入放射性示踪剂的有害影响阻碍了传统的电泳法和放射性化学测序法。通过分析水解磷蛋白，我们将提高完整质量分析的灵敏度，而全自动前体选择和PSD的使用将允许对磷酸肽进行快速MS2分析，以帮助确定当肽中存在不止一个潜在的磷酸化位点时的磷酸化位置。升级后的仪器所具有的质量精确度和分辨率对于鉴定由未知蛋白质产生的水解物片段将是非常有价值的。该仪器将适用于在进行还原之前和之后测量多肽的拟议方法，从而能够对含有二硫键的多肽进行PSD分析。索尔克研究所已有的其他仪器包括具有液体二次电离源和激光解吸电离源的双聚焦磁扇形质谱计、电喷雾离子陷阱质谱仪和带有PTH分析仪的气相测序仪。要求升级的飞行时间质谱仪是索尔克研究所强大的经典埃德曼测序方法的补充。该仪器将放置在MS设备中。重大的机构承诺将确保这一文书由训练有素的人员操作和维护。所有测量将在A·克雷格的监督下进行。

This is a request for a time-of-flight (TOF) mass spectrometer. The instrument will play a pivotal role in the research projects of many investigators at the Salk Institute and researchers at other academic institutions (see letters of support). We will obtain accurate mass and structural information on novel hormones, toxins, and growth factors and characterize the sites and nature of post-translational modifications in molecules of known primary structure. A group of 10 investigators has been identified whose research is dependent on analyses only possible with the requested instrument. The sensitivity of the instrument is essential to our current attempts to characterize novel peptides and proteins. Results obtained on a variety of unstable peptides illustrate the increased sensitivity available with pulsed ion extraction and the laser optics on the requested instrument compared with continuous extraction and the more rudimentary analysis currently available. The instrument will also be vital for identifying the site of phosphorylation in phosphoproteins where either the low level of phosphorylation or the deleterious effects of introducing a radioactive tracer prohibit conventional electrophoresis and radioactive chemical sequencing protocols. By analyzing the hydrolyzed phosphoprotein, we will increase the sensitivity of intact mass analysis while the use of fully automated precursor selection and PSD will allow rapid MS2 analysis of the phosphopeptide to help identify the site of phosphorylation when more than one potential site of phosphorylation exists in the peptide. The mass accuracy and resolution available with the upgraded instrument will be extremely valuable for the identification of hydrolysis fragments generated from 'unknown' proteins. The instrument will be amenable to a proposed approach of measuring a peptide both prior to and after carrying out reduction and thereby enabling PSD analysis of disulfide bridge-containing peptides. Other instruments already available at the Salk Institute include a double focusing magnetic sector mass spectrometer with both liquid secondary ionization and laser desorption ionization sources, an electrospray ion trap mass spectrometer, and gas phase sequencers with PTH analyzers. The requested upgraded TOF mass spectrometer is needed to complement the strong classical Edman sequencing approach at the Salk Institute. The instrument will be located in the MS Facility. A significant institutional commitment will ensure that this instrument is operated and maintained by trained personnel. All measurements will be made under the supervision of A. Craig.