THERMO COMPARISON BETWEEN LTQ AND VELOS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 在过去的十年中，高效液相色谱-电喷雾电离-串联质谱仪在高通量蛋白质组学分析方面取得了长足的进步，这在很大程度上得益于仪器的不断改进。高通量鉴定实验是以肽序列为基础的，主要通过使用串联质谱仪完成，离子陷阱和基于陷阱的仪器已成为广泛采用的分析平台。为了满足对表征深度和吞吐量日益苛刻的要求，我们提出了一种新开发的双压线性离子陷阱质谱仪(LTQ Velos)，其特点是通过新的源设计提高了灵敏度，并证明了实际周期比LTQ XL短2倍，同时改善或保持了MS/MS碎裂光谱的光谱质量。与现有平台相比，这些改进大大增加了对秀丽线虫复杂蛋白质组中蛋白质和独特多肽的检测和鉴定。进入质谱仪的离子通量大大增加，再加上对低丰度前体离子的分离改进，导致对低丰度多肽的检测增加。与LTQ XL相比，这些改进累积起来使面包师酵母(酿酒酵母)蛋白质组的渗透率大大提高。或者，新仪器上更快的周期时间可以为给定深度的蛋白质组分析提供更高的吞吐量，使用LTQ Velos在60分钟内识别出比使用LTQ XL在180分钟内识别出的更多的多肽和蛋白质。当质量分析的分辨率超过25000全宽的半最大值(FWHM)时，就有可能用同位素来分解一个小的完整蛋白质及其片段，从而为自上而下的实验打开了可能性。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The considerable progress in high-throughput proteomics analysis via liquid chromatography-electrospray ionization-tandem mass spectrometry over the past decade has been fueled to a large degree by continuous improvements in instrumentation. High-throughput identification experiments are based on peptide sequencing and are largely accomplished through the use of tandem mass spectrometry, with ion trap and trap-based instruments having become broadly adopted analytical platforms. To satisfy increasingly demanding requirements for depth of characterization and throughput, we present a newly developed dual-pressure linear ion trap mass spectrometer (LTQ Velos) that features increased sensitivity, afforded by a new source design, and demonstrates practical cycle times 2 times shorter than that of an LTQ XL, while improving or maintaining spectral quality for MS/MS fragmentation spectra. These improvements resulted in a substantial increase in the detection and identification of both proteins and unique peptides from the complex proteome of Caenorhabditis elegans, as compared to existing platforms. The greatly increased ion flux into the mass spectrometer in combination with improved isolation of low-abundance precursor ions resulted in increased detection of low-abundance peptides. These improvements cumulatively resulted in a substantially greater penetration into the baker's yeast (Saccharomyces cerevisiae) proteome compared to LTQ XL. Alternatively, faster cycle times on the new instrument allowed for higher throughput for a given depth of proteome analysis, with more peptides and proteins identified in 60 min using an LTQ Velos than in 180 min using an LTQ XL. When mass analysis was carried out with resolution in excess of 25 000 full width at half-maximum (fwhm), it became possible to isotopically resolve a small intact protein and its fragments, opening possibilities for top down experiments.