Rapidly quantitative analysis of gamma-glutamyltranspeptidase activity in the lysate and blood via a rational design of the molecular probe by matrix-assisted laser desorption ionization mass spectrometry
Rapidly quantitative analysis of gamma-glutamyltranspeptidase activity in the lysate and blood via a rational design of the molecular probe by matrix-assisted laser desorption ionization mass spectrometry
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通过基质辅助激光解吸电离质谱法合理设计分子探针，快速定量分析裂解物和血液中的γ-谷氨酰转肽酶活性
DOI：
10.1016/j.talanta.2019.120141
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发表时间：
2019
期刊：
影响因子：
6.1
通讯作者：
Guo Xinhua
中科院分区：
文献类型：
--
作者：
Wang Sheng;Xiao Chunsheng;Guo Liming;Ling Ling;Li Ming;Li Hongmei;Guo Xinhua
γ-谷氨酰转肽酶（GGT）在细胞谷胱甘肽/半胱氨酸稳态中起重要作用，是一种潜在的肿瘤生物标志物。在此，我们报告了一个合理设计的分子探针（Aq-ECG）通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）的GGT活性的快速和定量分析。该探针是一种水溶性分子，由具有紫外吸收性的芳香族蒽醌（Aq）和GGT可切割的谷胱甘肽（ECG）通过一步硫醇-烯反应共价连接在一起组成。蒽醌部分的作用不仅是增加GGT催化裂解后目标离子的分子量，使报告离子出现在高电子密度区，避免了基质离子的干扰，而且显著提高了报告离子的电离效率。此外，芳香Aq部分可以被自制的磁性氧化石墨烯材料选择性地捕获，并从复杂的混合物中分离目标。在优化的条件下，以Aq连接的甲基化谷胱甘肽（Aq-ECA）为内标，GGT活性量在1-50 U/L范围内呈线性关系，相关系数r2> 0.99。应用此探针的GGT水平在人血清样品从健康和肝癌患者已很容易地检测，结果是一致的，通过酶联免疫吸附测定。该方法还成功地应用于检测不同肿瘤/正常细胞中内源性GGT的含量以及丁酸钠（抗癌药物）对GGT活性的抑制能力。因此，一个简单的，敏感的和成本/时间经济的方法已被证明是准确定量GGT活性测定和筛选其抑制剂/抗癌药物通过使用功能分子探针。该方法通过取代探针的反应/报告部分，也可广泛应用于其他蛋白酶活性分析。
Gamma-glutamyl transpeptidase (GGT) plays an important role in cellular glutathione/cysteine homeostasis and is a potential tumor biomarker. Herein, we report a rationally designed molecular probe (Aq-ECG) for rapid and quantitative analysis of GGT activities via matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The probe is a water-soluble molecule consisting of an UV-absorptive aromatic anthraquinone (Aq) and a GGT cleavable glutathione (ECG) via one-step thiol-ene reaction covalently linked together. The function of anthraquinone part is not only to increase molecular mass of the target ions after GGT catalyzed cleavage enabling the report ions appearing in higherm/zregion avoiding matrix ion interference, but also to remarkably enhance the report ions ionization efficiency. Additionally, the aromatic Aq part can be selectively captured by home-made magnetic graphene oxide materials and separated the targets from complex mixtures. Under optimized conditions, when employing an Aq linked methylated-glutathione (Aq-ECA) as the internal standard, the GGT activity amount can be quantified in a linear range of 1–50 U/L with r2> 0.99. Applying this probe the GGT levels in human serum samples from both healthy and liver cancer patients have been readily detected; the results were consistent with those determined by an enzyme-linked immunosorbent assay. This method was also successfully applied for the detection of endogenous GGT amounts in different tumor/normal cells and the inhibition capability of sodium butyrate (an anticancer drug) to GGT activity. Thus, a simple, sensitive and cost/time economic method has been demonstrated for accurately quantitative GGT activity assay and screening of its inhibitors/anticancer drugs via the using of a functional molecular probe. This method is also widely applicable for other protease activity analysis by the replacement of reaction/report part of the probe.