Selective detection of 2‐nitrobenzenesulfenyl‐labeled peptides by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry using a novel matrix
Selective detection of 2‐nitrobenzenesulfenyl‐labeled peptides by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry using a novel matrix
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DOI：
10.1002/pmic.200500575
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发表时间：
2006-04
期刊：
影响因子：
3.4
通讯作者：
Ei-ichi Matsuo;C. Toda;Makoto Watanabe;Noriyuki Ojima;S. Izumi;Koichi Tanaka;S. Tsunasawa;O. Nishim
中科院分区：
文献类型：
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作者：
Ei-ichi Matsuo;C. Toda;Makoto Watanabe;Noriyuki Ojima;S. Izumi;Koichi Tanaka;S. Tsunasawa;O. Nishim
2-硝基苯硫基 (NBS) 方法可用于定量蛋白质组分析，该方法基于用 NBS 氯化物（12C6-NBSCl 或 13C6-NBSCl）对色氨酸残基进行稳定同位素标记。我们发现，3-羟基-4-硝基苯甲酸 (3H4NBA) 是比 2,5-二羟基苯甲酸 (DHB) 更适合通过 MALDI-四极杆 IT (QIT)-TOF MS 检测 NBS 标记肽的基质。此外，NBS 标记的肽被选择性电离，并在 NBS 标记和未标记的肽的混合物中进行检测。无需富集即可轻松检测到标记的配对峰，非配对的标记峰与未标记的污染肽明显区分开来，并且在 3H4NBA 基质上也选择性地检测到含硝基酪氨酸的肽，而硝基苯部分产生的副产物峰则被抑制。使用 3H4NBA 作为与 CHCA 的共基质提高了检测灵敏度，同时基本上保留了 3H4NBA 的选择性。当用于 NBS 方法和应用于具有硝基苯环的化合物的 MALDI-TOF MS 分析时，3H4NBA 基质在简单性、灵敏度和可用性方面具有巨大的优势。
The 2‐nitrobenzenesulfenyl (NBS) method, which is useful for quantitative proteome analysis, is based on stable isotope labeling of tryptophan residues with NBS chloride (12C6‐NBSCl or 13C6‐NBSCl). We found that 3‐hydroxy‐4‐nitrobenzoic acid (3H4NBA) is a more suitable matrix than 2,5‐dihydroxybenzoic acid (DHB) for detecting NBS‐labeled peptides by MALDI‐quadrupole IT (QIT)‐TOF MS . Furthermore, NBS‐labeled peptides were selectively ionized and detected in a mixture of NBS‐labeled and unlabeled peptides. Labeled paired peaks were easily detected without enrichment, nonpaired labeled peaks were clearly distinguished from unlabeled contaminating peptides, and nitrotyrosine‐containing peptides were also selectively detected on the 3H4NBA matrix, while by‐product‐peaks arising from nitrobenzene moieties were suppressed. The use of 3H4NBA as a comatrix with CHCA improved the sensitivity of detection while substantially retaining the selectivity of 3H4NBA. The 3H4NBA matrix offers great advantages in terms of simplicity, sensitivity, and usability when used for the NBS method and for MALDI‐TOF MS analysis applied to compounds having a nitrobenzene ring.