Proteomics technologies for the global identification and quantification of proteins

Area of Science:

• Proteomics and its role in biological discovery.

Background:

• Proteomics offers significant opportunities for advancing biological understanding and identifying biomarkers.
• Tandem mass spectrometry (MS) is central to proteomics, but requires complementary technologies like protein separation, genomics, and bioinformatics.

Purpose of the Study:

• To provide a non-specialist introduction to proteomics, detailing key methods for protein identification and quantification.
• To highlight the opportunities and challenges in achieving comprehensive proteomic analysis.

Main Methods:

• Predominant protein identification workflows include 2D electrophoresis (2DE) coupled with MS, liquid chromatography-MS (LC-MS), and GeLC-MS.
• Protein quantification methods include Difference Gel Electrophoresis (DIGE) and MS-based approaches like Isobaric Tags for Relative and Absolute Quantification (iTRAQ) and Stable Isotope Labeling by Amino Acids (SILAC).
• Critical sample preparation techniques include subcellular fractionation, differential detergent solubilization, immunodepletion of abundant proteins, and sample enrichment (e.g., phosphopeptide purification).

Main Results:

• Proteomics has already yielded significant insights into biological functions.
• Ongoing technological improvements are enhancing the capabilities of proteomics.
• Challenges remain in achieving full proteomic coverage, particularly for low-abundance, poorly soluble proteins, and multiprotein complexes.

Conclusions:

• Proteomics technologies are crucial for biological understanding and biomarker discovery.
• Despite challenges, proteomics continues to provide valuable biological insights and is expected to increasingly fulfill its promise in biomarker discovery.