Liquid AP-UV-MALDI enables stable ion yields of multiply charged peptide and protein ions for sensitive analysis by mass spectrometry.
Liquid AP-UV-MALDI enables stable ion yields of multiply charged peptide and protein ions for sensitive analysis by mass spectrometry.
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DOI：
10.1002/anie.201208628
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发表时间：
2013-02-18
影响因子：
16.6
通讯作者：
Dreisewerd, Klaus
中科院分区：
文献类型：
--
作者：
Cramer, Rainer;Pirkl, Alexander;Hillenkamp, Franz;Dreisewerd, Klaus
在生物质谱（MS）中，主要采用两种电离技术来分析较大的生物分子，例如多肽。这些是纳米电喷雾电离[1，2]（nanoESI）和基质辅助激光解吸/电离[3，4]（MALDI）。这两种技术都被认为是“软”的，允许完整的分子分析物物种的解吸和电离，从而成功的质谱分析。这两种电离技术之间的主要区别之一在于它们产生多电荷离子的能力。MALDI通常产生单电荷肽离子，而nanoESI很容易提供多电荷离子，即使是质量低至1000 Da的肽。高电荷离子的产生是期望的，因为这允许使用质量分析器，例如离子阱（包括轨道阱）和混合四极仪器，其通常仅提供有限的m/z范围（< 2000-4000）。它还可以使用碰撞诱导解离（CID）和电子捕获/转移解离（ECD/ETD）等技术结合串联MS（MS/MS）获得更多信息的碎片光谱。[5，6]因此，在需要肽测序或通常需要通过MS/MS对生物分子进行结构解析的研究领域中使用ESI具有明显的优势。尽管如此，MALDI对污染物和添加剂具有更高的耐受性，易于操作，高速和自动化样品制备和分析的潜力以及MS成像能力，使其成为一种电离技术，可以覆盖ESI不太适合的生物分析领域。[7，8]如果这些优势可以与多电荷离子的分析能力相结合，新的仪器配置和基于MALDI MS（/MS）的大规模蛋白质组学分析将变得可行。在以前的论文中，液体基质在IR和UV-MALDI MS中的优点得到了证明。[9-11]对于液体UVMALDI MS，这些好处包括在数千次激光照射中稳定且持久的分析物离子产率，以及这些基质容纳基质添加剂的能力，这些添加剂可以显着改变MALDI样品的性质。已经表明，液体基质的这些性质可以用于高度准确的分析物定量[11]和MALDI样品pH值的广泛覆盖。[12]较宽的pH值范围使MALDI样品中的胰蛋白酶消化和MS检测其产物成为可能。[12]大气压（AP）-MALDI已被证明有助于形成多电荷蛋白质以及肽离子，尽管灵敏度较低并且必须使用红外激光。[13]双电荷肽离子也在中等压力下的UV-MALDI MS和真空压力下使用IR-MALDI MS记录，[14]但信号强度比单电荷离子低得多。讨论了通过改变基质和离子源设计来产生高产率多电荷离子的可能性。[14]随后，Zenobi等人报道了另一种MALDI样品制备方法，以增加多电荷离子的产率。其中之一采用电喷雾沉积至少200 pmol的分析物在各种预形成的MALDI基质层，显示在特定条件下，尽管在低信噪比下，也可以检测到高度带电的胰岛素离子。[15]在此，我们报告了使用液体UV-MALDI基质和具有离子转移管的AP离子源实现多电荷肽和蛋白质离子的高和长产率的进展，所述离子转移管可以在高达400 ℃的可变升高温度下使用。液体...
In biological mass spectrometry (MS), two ionization techniques are predominantly employed for the analysis of larger biomolecules, such as polypeptides. These are nano-electrospray ionization [1, 2](nanoESI) and matrix-assisted laser desorption/ionization [3, 4](MALDI). Both techniques are considered to be “soft”, allowing the desorption and ionization of intact molecular analyte species and thus their successful mass-spectrometric analysis. One of the main differences between these two ionization techniques lies in their ability to produce multiply charged ions. MALDI typically generates singly charged peptide ions whereas nanoESI easily provides multiply charged ions, even for peptides as low as 1000 Da in mass. The production of highly charged ions is desirable as this allows the use of mass analyzers, such as ion traps (including orbitraps) and hybrid quadrupole instruments, which typically offer only a limited m/z range (< 2000–4000). It also enables more informative fragmentation spectra using techniques such as collisioninduced dissociation (CID) and electron capture/transfer dissociation (ECD/ETD) in combination with tandem MS (MS/MS).[5, 6] Thus, there is a clear advantage of using ESI in research areas where peptide sequencing, or in general, the structural elucidation of biomolecules by MS/MS is required. Nonetheless, MALDI with its higher tolerance to contaminants and additives, ease-of-operation, potential for highspeed and automated sample preparation and analysis as well as its MS imaging capabilities makes it an ionization technique that can cover bioanalytical areas for which ESI is less suitable.[7, 8] If these strengths could be combined with the analytical power of multiply charged ions, new instrumental configurations and large-scale proteomic analyses based on MALDI MS (/MS) would become feasible. In previous papers, the benefits of liquid matrices in IR-and UV-MALDI MS were demonstrated.[9–11] For liquid UVMALDI MS, these benefits include a stable and durable analyte ion yield over thousands of laser shots and the capacity of these matrices to accommodate matrix additives that can change the properties of the MALDI sample significantly. It has been shown that these properties of liquid matrices can be exploited for highly accurate analyte quantitation [11] and a wide coverage of MALDI sample pH values.[12] The broad pH range enabled tryptic digestion within the MALDI sample and the detection of its products by MS.[12]Atmospheric pressure (AP)-MALDI has been shown to facilitate the formation of multiply charged protein as well as peptide ions, although the sensitivity is lower and an infrared laser must be employed.[13] Doubly charged peptide ions were also recorded under intermediate pressure in UV-MALDI MS and under vacuum pressure using IR-MALDI MS,[14] but with a much lower signal intensity than for singly charged ions. The possibility of generating multiply charged ions with higher yield by changing the matrix and ion-source design was discussed.[14] Subsequently, Zenobi et al. reported alternative MALDI sample-preparation methods to increase the yield of multiply charged ions. One of these employed electrospray deposition of at least 200pmol of analyte on various preformed MALDI matrix layers, showing that under specific conditions highly charged insulin ions can be detected albeit at a low signal-to-noise ratio.[15] Herein, we report progress in achieving high and prolonged yields of multiply charged peptide and protein ions using liquid UV-MALDI matrices and an AP ion source with an ion transfer tube that can be used at variable elevated temperatures of up to 4008C. The liquid …
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DOI：
10.1016/j.jasms.2010.06.012
发表时间：
2010-10
影响因子：
3.2
作者：
Sterling HJ;Daly MP;Feld GK;Thoren KL;Kintzer AF;Krantz BA;Williams ER
通讯作者：
Williams ER
影响因子：
3.4
作者：
Cramer, R;Corless, S
通讯作者：
Corless, S
DOI：
10.1007/s13361-012-0414-y
发表时间：
2012-10-01
影响因子：
3.2
作者：
Trimpin, Sarah;Wang, Beixi;McEwen, Charles N.
通讯作者：
McEwen, Charles N.
影响因子：
7.4
作者：
Koenig, Simone;Kollas, Oliver;Dreisewerd, Klaus
通讯作者：
Dreisewerd, Klaus
DOI：
10.1016/j.jasms.2007.11.013
发表时间：
2008-02-01
影响因子：
3.2
作者：
Glish, Gary L.;Burinsky, David J.
通讯作者：
Burinsky, David J.