We have developed a surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) approach for detection of five targeted metabolites, glycine (Gly), alanine (Ala), phosphocholine (PCho), glucose (Glu), and glutathione (GSH), in cells. The optimal SALDI-MS condition for the quantitation of the analytes is 0.5 mM ammonium citrate solution (pH 5.0) containing 15 nM Au NPs. Using sucralose as an internal standard, this approach allows reproducible quantitation of Ala, Gly, Glu, GSH, and PCho down to 2.7, 8.9, 2.7, 5.2, and 29.3 μM, respectively. The concentrations of each analyte in the tested breast cancer cells (MCF7, MDA-MB-231) and the nontumoral counterpart (MCF10A) are different. This assay has been validated by the determination of the activities of two inhibitors (2-deoxy-d-glucose and D609) and an anticancer drug (paclitaxel) for the cells by simply monitoring the concentration changes of the five analytes. Our study clearly shows that this simple, sensitive, reproducible, and rapid SALDI-MS approach holds great potential for drug screening through quantitation of target metabolites.

中文翻译：

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通过表面辅助激光解吸/电离质谱法检测细胞中的代谢物

我们已经开发了一种表面辅助激光解吸/电离质谱（SALDI-MS）方法，用于检测五种目标代谢物：甘氨酸（Gly），丙氨酸（Ala），磷胆碱（PCho），葡萄糖（Glu）和谷胱甘肽（GSH） ），在单元格中。用于分析物定量的最佳SALDI-MS条件是含有15 nM Au NP的0.5 mM柠檬酸铵溶液（pH 5.0）。使用三氯蔗糖作为内标，该方法可对低至2.7、8.9、2.7、5.2和29.3μM的Ala，Gly，Glu，GSH和PCho进行可重复的定量。被测乳腺癌细胞（MCF7，MDA-MB-231）和非肿瘤对应物（MCF10A）中每种分析物的浓度均不同。通过测定两种抑制剂（2-脱氧-d-葡萄糖和D609）以及用于细胞的抗癌药物（紫杉醇），只需监测五种分析物的浓度变化即可。我们的研究清楚地表明，这种简单，灵敏，可重现和快速的SALDI-MS方法具有通过定量目标代谢物进行药物筛选的巨大潜力。