MALDI-induced Fragmentation of Leucine enkephalin, Nitro-Tyr Leucine Enkaphalin, and d(5)-Phe-Nitro-Tyr Leucine Enkephalin.
MALDI-induced Fragmentation of Leucine enkephalin, Nitro-Tyr Leucine Enkaphalin, and d(5)-Phe-Nitro-Tyr Leucine Enkephalin.
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DOI：
10.1016/j.ijms.2008.08.020
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发表时间：
2009-10-15
影响因子：
1.8
通讯作者：
Desiderio DM
中科院分区：
文献类型：
--
作者：
Zhan X;Desiderio DM
本研究的长期目标是使用MALDI MS和MS/MS研究体外含硝基酪氨酸肽的裂解模式，以帮助解释人体组织和体液中内源性硝基蛋白的MS鉴定。短期目标是研究合成亮氨酸脑啡肽，硝基-酪氨酸-亮氨酸脑啡肽，和d5-苯丙氨酸-硝基-酪氨酸-亮氨酸脑啡肽与真空基质辅助激光解吸/电离线性离子阱质谱仪（vMALDI-LTQ）。结果表明，紫外激光诱导硝基的光化学分解。尽管光化学分解降低了离子强度并使MS光谱复杂化，但对该独特分解模式的识别明确地鉴定了硝基酪氨酸。a4-和b4-离子是这三种合成肽的MS/MS谱中发现的最强碎片离子。与未修饰的肽相比，更多的碰撞能量优化了硝基肽的片段化，增加了a4-离子的强度，并降低了b4-离子的强度。优化的激光能量密度使硝基肽的裂解最大化。MS 3分析证实了MS 2衍生的氨基酸序列，但需要更多的样品。为了检测硝基肽，vMALDI-LTQ的灵敏度对于MS检测为1 fmol，对于MS 2检测为10 fmol; S/N比约为10 fmol。50：1在这些研究中。这些数据是重要的低丰度的内源性硝基蛋白的分析，优先富集硝基蛋白和优化的质谱参数。
The long-term objective of this study is to use MALDI MS and MS/MS to study the fragmentation pattern of in vitro nitrotyrosine-containing peptides in order to assist the interpretation of MS-identification of endogenous nitroproteins in human tissues and fluids. The short-term objective is to study synthetic leucine enkephalin, nitro-Tyr-leucine enkephalin, and d5-Phe-nitro-Tyr-leucine enkephalin with a vacuum matrix-assisted laser desorption/ionization linear ion-trap mass spectrometer (vMALDI-LTQ). The results demonstrated the UV laser-induced photochemical decomposition of the nitro group. Although photochemical decomposition decreased the ion intensity and complicated the MS spectrum, the recognition of that unique decomposition pattern unambiguously identified a nitrotyrosine. The a4- and b4-ions were the most-intense fragment ions found in the MS/MS spectra for those three synthetic peptides. Compared to the unmodified peptides, more collision energy optimized the fragmentation of the nitropeptide, increased the intensity of the a4-ion, and decreased the intensity of the b4-ion. Optimized laser fluence maximized the fragmentation of the nitropeptide. MS3 analysis confirmed the MS2-derived amino acid sequence, but required much more sample. To detect a nitropeptide, the sensitivity of vMALDI-LTQ is 1 fmol for MS detection and 10 fmol for MS2 detection; the S/N ratio was ca. 50:1 in those studies. Those data are important for an analysis of low-abundance endogenous nitroproteins, where preferential enrichment of nitroproteins and optimized mass spectrometry parameters are used.
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影响因子：
4.4
作者：
Justilien, Verline;Pang, Ji-Jing;Lewin, Alfred S.
通讯作者：
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影响因子：
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2
作者：
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影响因子：
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作者：
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Bonetto, V
影响因子：
2.5
作者：
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d'Ischia, M