色谱 ›› 2020, Vol. 38 ›› Issue (10): 1125-1132.DOI: 10.3724/SP.J.1123.2020.03003

• 专论与综述 • 上一篇    下一篇

基于毛细管电泳技术的高灵敏度蛋白质组学技术发展

杨云1,2, 田瑞军1,*()   

  1. 1 南方科技大学化学系, 广东 深圳 518055
    2 香港科技大学化学及生物工程学系, 香港 999077
  • 收稿日期:2020-03-04 出版日期:2020-10-08 发布日期:2020-12-11
  • 通讯作者: 田瑞军
  • 作者简介:田瑞军.E-mail:tianrj@sustech.edu.cn
  • 基金资助:
    国家自然科学基金(21575057)

Recent progress in capillary electrophoresis-based high-sensitivity proteomics

YANG Yun1,2, TIAN Ruijun1,*()   

  1. 1 Department of Chemistry, South University of Science and Technology, Shenzhen 518055, China
    2 Department of Chemical and Biological Engineering, the Hong Kong University of Science & Technology, Hong Kong 999077, China
  • Received:2020-03-04 Online:2020-10-08 Published:2020-12-11
  • Contact: TIAN Ruijun
  • Supported by:
    National Natural Science Foundation of China(21575057)

摘要:

近年来,蛋白质组学技术在样品前处理、分离技术和质谱检测技术方面获得了快速发展,已经可以实现在几小时内对上万种蛋白的同时定性和定量分析。然而,目前的主流蛋白质组学技术仍无法满足极微量生物样品,尤其是单细胞样品的组学分析需求。毛细管电泳分离技术具有峰宽窄、柱效高、样品用量少等优势,是与高分辨质谱在线联用的理想选择之一。该文评述了集成化和在线样品前处理以及主流的纳升液相色谱-质谱联用系统在高灵敏度蛋白质组学分析领域的发展现状和挑战,认为该领域的重要技术挑战之一在于目前的纳升液相色谱分离已经无法完全匹配现代高分辨质谱超过40 Hz的超高扫描速度,从而导致质谱使用效率的降低。针对上述技术挑战,该文重点探讨了毛细管电泳-质谱联用技术的独特技术优势和潜在发展机遇,主要包括:(1)面向微量酶解多肽样品的高柱效毛细管电泳分离。通过采用毛细管电色谱可以进一步改善毛细管电泳柱容量不足的局限;(2)面向高灵敏度分析的无鞘液/鞘液接口开发;(3)高效毛细管电泳分离与高扫描速度质谱检测的协同化使用。总之,我们预期毛细管电泳-质谱联用技术的进一步发展有望在针对单细胞等超微量生物学样品的蛋白质组学分析中获得更广泛的应用。

关键词: 毛细管电泳-质谱联用, 蛋白质组学, 鞘液接口, 集成化样品前处理

Abstract:

In recent years, proteomic techniques have undergone rapid progress in terms of sample pretreatment, separation, and mass spectrometry (MS) detection. The current MS-based proteomic techniques can be used to identify up to 10000 proteins both qualitatively and quantitatively within a few hours. However, the current mainstream proteomic approaches do not fulfill the need to analyze minute amounts of biological samples, especially rare cells and single mammalian cells. Capillary electrophoresis (CE)-based separation offers many advantages, such as narrow peaks, high separation efficiency, and low sample requirement, which make it an ideal separation approach for combination with high-resolution MS. We have reviewed the state-of-the-art development of integrated and online sample preparation methods and nanoscale liquid chromatography-mass spectrometry (nanoLC-MS) for high-sensitivity proteomics, and described the associated challenges. Integrated and online sample preparation methods can minimize sample loss and improve lysis and digestion efficiencies. The simple and integrated spintip-based proteomics technology (SISPROT) developed by our group has shown robust performance for the comprehensive profiling of various types of samples and the sensitive analysis of small numbers of cells, down to a few hundred. A few groups have applied integrated/online sample preparation methods, such as nanodroplet processing in one pot for trace samples (nanoPOTS) and integrated proteome analysis system for one cell (iPAD-1), to achieve the identification of hundreds of proteins from a single HeLa cell. We propose that one of the key technical challenges in this field is that the performance of current nanoLC separation techniques cannot match modern high-resolution MS techniques, with ultrahigh scan rates of over 40 Hz; therefore, the insufficient chromatographic performance results in reduced utilization of MS/MS scan capacity. Wide chromatographic peaks result in insufficient precursors to trigger MS/MS scans and redundant sampling, irrespective of whether dynamic exclusion has been enabled. In view of the above mentioned technical challenges, we have focused on discussing the unique technical advantages and potential opportunities of CE-MS, which mainly include the following. (1) High-performance capillary electrophoresis (HPCE) separation for minute amounts of tryptic peptide samples. Capillary electrochromatography can further improve the column capacity limit of HPCE. (2) CE-MS interfaces for high-sensitivity proteomics. Although sheath liquid interfaces have proven versatile and robust and are currently more commonly used, sheathless interfaces can significantly enhance the signal/noise ratio owing to decreased analyte dilution and background noise. Thus, sheathless interfaces are potentially more suitable for ultrasensitive proteomics. (3) Synergetic utilization of HPCE separation and MS detection at high scan rates. The most promising way to fully utilize the ultrahigh scan rates of modern high-resolution MS is to enhance the quality of peptide separation. Narrower peptide peaks in HPCE separation may greatly reduce redundant sampling and boost sensitivity. Overall, we anticipate that, after further improvement, CE-MS-based proteomics will be more widely applied to proteomic analysis of minute amounts of biological samples, such as single mammalian cells. Furthermore, more sensitive data acquisition modes, such as data-independent acquisition, may be used for global proteomic profiling, and parallel reaction monitoring may be used to target a limited number of important proteins. Matching between runs and machine learning algorithms may improve the accuracy of proteomic analysis of minute amounts of samples.

Key words: capillary electrophoresis-mass spectrometry (CE-MS), proteomics, sheath liquid interface, integrated sample preparation