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Published on: August 2, 2018
Phosphopeptide microarrays for comparative proteomic profiling of cellular lysates
Liqian Gao1, Hongyan Sun, Mahesh Uttamchandani
1National University of Singapore, Singapore, Republic of Singapore.
Abstract:
Protein phosphorylation is one of the most important and well-studied posttranslational modifications. Aberrant phosphorylation causes a wide spectrum of diseases, including cancers. As a result, many of the proteins involved in these pathways are seen as vital drug targets and biomarkers in treatment and diagnosis. The availability of broad-based platforms that identify changes across cellular states is critical in understanding unique disease characteristics and changes at the proteomic level. To highlight how microarrays can be applied in this regard, we describe here a comparative proteomic profiling method using two-color sample labeling and application on phosphopeptide microarrays, followed by a pull-down strategy and MS-based protein identification. This strategy has been applied to uncover candidate biomarkers in breast cancer and colon cancer cell lines. Apart from the synthesis of the phosphopeptide libraries and growth/isolation of cellular lysates, the protocol takes approximately 15 days to complete, once key steps have been optimized, and can be readily extended to other similarly complex biological specimens/samples.
Insights
This study presents a phosphopeptide microarray method for comparative proteomic profiling. This approach identifies potential cancer biomarkers by analyzing protein phosphorylation changes in cell lines.
Area of Science:
- Biochemistry
- Proteomics
- Molecular Biology
Background:
- Protein phosphorylation is a critical posttranslational modification implicated in various diseases, including cancers.
- Identifying aberrant phosphorylation patterns is vital for discovering drug targets and diagnostic biomarkers.
- Advanced proteomic profiling platforms are essential for understanding disease-specific molecular changes.
Purpose of the Study:
- To develop and showcase a comparative proteomic profiling method utilizing phosphopeptide microarrays.
- To demonstrate the application of this method for identifying novel biomarkers in cancer.
- To establish a robust protocol for proteomic analysis in complex biological samples.
Main Methods:
- Employs a two-color sample labeling strategy for comparative analysis.
- Utilizes phosphopeptide microarrays for high-throughput screening of phosphorylation events.
- Integrates a pull-down strategy followed by mass spectrometry (MS) for protein identification.
Main Results:
- Successfully applied the strategy to uncover candidate biomarkers in breast and colon cancer cell lines.
- The protocol, once optimized, can be completed in approximately 15 days.
- Demonstrated the method's adaptability for other complex biological specimens.
Conclusions:
- Phosphopeptide microarrays offer a powerful tool for comparative proteomic profiling.
- This method facilitates the discovery of potential biomarkers for cancer diagnosis and treatment.
- The described protocol is a valuable addition to the field of cancer proteomics.
