Targeted proteomics technology for accurate quantitative single-cell proteomics
EMSL Project ID
60292
Abstract
Multi-omics characterization of a broad spectrum of small subpopulations of cells between tumors and within individual tumors at the single-cell resolution is crucial to achieve understanding of a complete disease biology. Furthermore, biologically important clinical specimens are available in low quantity (e.g., <10 tumor cells), requiring advanced single-cell technologies for effective analysis. However, single-cell proteomics technologies are lagging far behind other omics technologies. Antibody-based immunoassays are used primarily for targeted single-cell proteomics, but they have inherent limitations (e.g., low multiplex), and generally lack quantitation accuracy. Mass spectrometry (MS)-based targeted proteomics has emerged as an alternative for broad accurate quantification. However, current single-cell MS can only allow for relative quantification of ~870 proteins from single mammalian cells. There are three major challenges in single-cell MS for accurate quantitative single-cell proteomics: 1) ineffective processing of single cells, 2) insufficient MS sensitivity and low sample throughput, and 3) lacking well-characterized universal internal standard (UIS). To address these challenges, we propose to develop a single-cell MS system for rapid accurate analysis of single-cell proteome. The feasibility is strongly supported by our recent progress in many aspects of technology development . The single-cell MS system will be developed through 1) establishing super-SILAC (stable isotope labeling with amino acids in cell culture) as both proteome carrier and UIS, 2) incorporation of proteome carrier super-SILAC (cSILAC) into the sample preparation workflow for robust processing of single cells, and 3) leveraging cutting-edging LC and MS technologies developed at PNNL with integration of ultralow-flow LC separation, high-efficiency ion source, and ultrafast high-resolution ion mobility separation for significantly improving both MS sensitivity and sample throughput. Super-SILAC will be characterized as UIS for absolute quantification with crude peptide standards, whose purity will be cost-effectively accurately determined using a combined lanthanide labeling and ICP-MS method. We anticipate that the new MS system will eventually become a convenient indispensable tool not only for quantitative single-cell proteomics but also for routine analysis of very small samples (e.g., rare cells). In turn, it will make substantial contributions to current biomedical research.
Project Details
Start Date
2022-02-14
End Date
N/A
Status
Active
Released Data Link
Team
Principal Investigator
Team Members