Hofstadler S A, Swanek F D, Gale D C, Ewing A G, Smith R D
Chemical Sciences Department, Pacific Northwest Laboratory, Richland, Washington 99352, USA.
Anal Chem. 1995 Apr 15;67(8):1477-80. doi: 10.1021/ac00104a028.
The combination of capillary electrophoresis (CE) with electrospray ionization (ESI) mass spectrometry has proven to be broadly applicable to a wide range of biologically important compounds. When combined with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry, the combined method, in addition to high-resolution separations, affords high-resolution precision mass measurements for analytes separated from complex mixtures. Direct chemical analysis of single cells has received considerable attention in recent years; the single cell approach provides a major step toward answering important questions in the field of cellular biochemistry. In this work we present preliminary results which demonstrate the feasibility of using the CE-ESI-FTICR combination as a high-performance detection scheme for the analysis of cellular proteins acquired directly from small populations (i.e., 5-10) of intact living cells. The human erythrocyte was chosen as a model system owing to its availability, relatively homogeneous composition, and thorough documentation of contents by previous researchers. In this work we demonstrate the on-line acquisition of high-resolution mass spectra (average resolution > or = 45,000 fwhm) of both the alpha and the beta chains of hemoglobin acquired from the injection of 10 human erythrocytes (corresponding to 4.5 fmol of hemoglobin). Given the extremely small volume of the human erythrocyte (typically 87 fl/cell), the techniques implemented here should also be adaptable to the study of larger mammalian cell systems.
毛细管电泳（CE）与电喷雾电离（ESI）质谱联用已被证明广泛适用于多种具有生物学重要性的化合物。当与傅里叶变换离子回旋共振（FTICR）质谱联用时，这种联用方法除了能实现高分辨率分离外，还能对从复杂混合物中分离出的分析物进行高分辨率精确质量测量。近年来，单细胞的直接化学分析受到了广泛关注；单细胞方法为解答细胞生物化学领域的重要问题迈出了重要一步。在这项工作中，我们展示了初步结果，证明了使用CE - ESI - FTICR联用作为一种高性能检测方案来分析直接从小群体（即5 - 10个）完整活细胞中获取的细胞蛋白质的可行性。由于人类红细胞易于获取、组成相对均匀且先前研究人员已对其成分进行了详尽记录，因此被选为模型系统。在这项工作中，我们展示了通过注入10个人类红细胞（相当于4.5飞摩尔血红蛋白）在线获取血红蛋白α链和β链的高分辨率质谱（平均分辨率≥45,000半高宽）。鉴于人类红细胞的体积极小（通常为87飞升/细胞），这里所采用的技术应该也适用于更大的哺乳动物细胞系统的研究。
