Introduction of 4-Chloro-α-cyanocinnamic Acid Liquid Matrices for High Sensitivity UV-MALDI MS
Introduction of 4-Chloro-α-cyanocinnamic Acid Liquid Matrices for High Sensitivity UV-MALDI MS
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DOI：
10.1021/pr901089j
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发表时间：
2010-04-01
影响因子：
4.4
通讯作者：
Cramer, Rainer
中科院分区：
文献类型：
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作者：
Towers, Mark W.;Mckendrick, John E.;Cramer, Rainer
基质辅助激光解吸电离(MALDI)是分析不稳定大分子的质谱学中的一种关键电离技术。关于MALDI及其在高灵敏度MS中的应用，一个重要的研究和改进领域是基质设计和样品制备。最近，4-氯-α-氰基肉桂酸(CICCA)作为一种新的合理设计的基质被引入，并被报道提供了一种改进的分析性能，通过肽质量图谱(PMM)获得的蛋白质摘要序列覆盖率的增加证明了这一点(Jaskolla，T.W.；等人)。程序娜塔莉。阿卡德。SCI。美国2008年，705年，12200-12205)。这种新的基质有可能成为常用的和非常成功的α-氰基-4-羟基肉桂酸(CHCA)的一种更好的替代品。通过开发和优化以CICCA为主要生色团的离子液体基质(ILM)和液体支撑基质(LSM)和MALDI基质化合物，我们将这一设计向前推进了一步。这些新的液体基质具有更大的样品均匀度和更简单的形态。我们从研究中获得的数据显示，与传统的CHCA晶体基质和含有CICCA的ILM相比，BSA消化的序列覆盖率有所提高，其性能与在单个MALDI样品液滴中制备的CICCA晶体基质相似，最低可达1fmol的BSA消化，电流灵敏度水平在attomol范围内。LSM对常用的缓冲剂碳酸氢铵等污染具有很高的耐受性。
Matrix-assisted laser desorption/ionization (MALDI) is a key ionization technique in mass spectrometry (MS) for the analysis of labile macromolecules. An important area of study and improvements in relation to MALDI and its application in high-sensitivity MS is that of matrix design and sample preparation. Recently, 4-chloro-alpha-cyanocinnamic acid (CICCA) has been introduced as a new rationally designed matrix and reported to provide an improved analytical performance as demonstrated by an increase in sequence coverage of protein digests obtained by peptide mass mapping (PMM) (Jaskolla, T. W.; et al. Proc. Natl. Acad. Sci. U.S.A. 2008, 705, 12200-12205). This new matrix shows the potential to be a superior alternative to the commonly used and highly successful alpha-cyano-4-hydroxycinnamic acid (CHCA). We have taken this design one step further by developing and optimizing an ionic liquid matrix (ILM) and liquid support matrix (LSM) using CICCA as the principle chromophore and MALDI matrix compound. These new liquid matrices possess greater sample homogeneity and a simpler morphology. The data obtained from our studies show improved sequence coverage for BSA digests compared to the traditional CHCA crystalline matrix and for the CICCA-containing ILM a similar performance to the CICCA crystalline matrix down to 1 fmol of BSA digest prepared in a single MALDI sample droplet with current sensitivity levels in the attomole range. The LSMs show a high tolerance to contamination such as ammonium bicarbonate, a commonly used buffering agent.