Quantification of selenium-tagged proteins in human plasma using species-unspecific isotope dilution ICP-DRC-qMS coupled on-line with anion exchange chromatography
Quantification of selenium-tagged proteins in human plasma using species-unspecific isotope dilution ICP-DRC-qMS coupled on-line with anion exchange chromatography
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DOI：
10.1039/b804935a
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发表时间：
2008-10
影响因子：
3.4
通讯作者：
Ming Xu;Limin Yang;Qiuquan Wang
中科院分区：
文献类型：
--
作者：
Ming Xu;Limin Yang;Qiuquan Wang
建立了电感耦合等离子体动态反应池-四极杆质谱（ICP-DRC-qMS）-阴离子交换色谱（AEC）联用技术，用于人血浆中硒标记蛋白质的定量分析。在动态反应池中采用甲烷作为反应气体，实现了不受~（40）Ar ~（2+）和~（79）BrH ~+光谱干扰的~（80）Se测定。硒蛋白P（SelP）、谷胱甘肽过氧化物酶（GPx）、硒白蛋白（SeAlb）等5种硒存在形式和2种未知硒存在形式本文用原子吸收法分离了5名健康人血浆中的硒（U_1和U_2），并测定了硒在SelP、GPx、SeAlb、U_1和U_2中的分布。通过ICP-DRC-qMS使用物种非特异性同位素稀释（80 Se/77 Se）测定了约45.5%、19.1%、15.1%、2.9%和8.1%的硒。基于硒的检测限（DL）（0.54 ng mL−1），我们估计SelP和GPx的DL分别为0.59 pmol mL−1和1.7 pmol mL−1。通过硒标记蛋白质中硒原子的化学计量，成功定量了SelP（2.7 ± 0.1 μg mL−1）和GPx（5.4 ± 0.2 μg mL−1）。
Inductively coupled plasma dynamic reaction cell-quadrupole mass spectrometry (ICP-DRC-qMS) coupled on-line with anion exchange chromatography (AEC) has been developed for the quantification of selenium-tagged proteins in human plasma. Methane was employed as a reaction gas in the dynamic reaction cell to achieve the determination of 80Se free of spectroscopic interference from 40Ar2+ and 79BrH+. Five selenium species including selenoprotein P (SelP), glutathione peroxidase (GPx), selenoalbumin (SeAlb), and two unknown selenospecies (U1 and U2) in a pooled plasma sample from five healthy people were separated using AEC, and the distribution of selenium in SelP, GPx, SeAlb, U1 and U2 (about 45.5%, 19.1%, 15.1%, 2.9% and 8.1%) was determined by ICP-DRC-qMS using species-unspecific isotope dilution (80Se/77Se). Based on the detection limit (DL) of selenium (0.54 ng mL−1), we estimated that the DLs for SelP and GPx were 0.59 pmol mL−1 and 1.7 pmol mL−1, respectively. Through the stoichiometry of the selenium atom in the selenium-tagged proteins, SelP (2.7 ± 0.1 μg mL−1) and GPx (5.4 ± 0.2 μg mL−1) were successfully quantified.