Single Cell Chemical Proteomics with Membrane-Permeable Activity-Based Probe for Identification of Functional Proteins in Lysosome of Tumors

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• 作者：Dongjuan Chen ; Fengkai Fan ; Xingfu Zhao ; Fei Xu ; Peng Chen ; Jie Wang ; Lin Ban ; Zhihua Liu ; Xiaojun Feng ; Yuhui Zhang ; Bi-Feng Liu
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：February 16, 2016
• 年：2016
• 卷：88
• 期：4
• 页码：2466-2471
• 全文大小：349K
• ISSN：1520-6882

文摘

Proteomics at single-cell resolution can help to identify the heterogeneity among cell populations, shows more and more significance in current chemistry and biology. In this work, we demonstrated a new single cell chemical proteomic (SCCP) strategy with a membrane-permeable activity-based probe (ABP) to characterize the functional proteins in lysosome located in the cytosol. The ABP targeted to the cysteine cathepsin family protein, CpFABP-G, was designed for cysteine cathepsins labeling. The labeled HeLa cell of a cancer cell line was injected into a capillary and was lysed by SDS solution with heating. The lysate was then online readout by capillary electrophoresis-laser-induced fluorescence method. Due to the employment of highly specified ABP kicking out the uncorrelated proteins, the expression of cysteine cathepsins in individual HeLa cells was easily detected, and heterogeneity among those HeLa cells was readily discriminated. Further work was concentrated on SCCP analysis of the mouse leukemia cell of monocyte macrophage (RAW264.7). It was for the first time identifying two expression modes of cysteine cathepsins in RAW264.7, which could be undermined by the analysis of cell populations. We believed that SCCP would be one of the powerful alternatives for proteomics at single-cell resolution.