What Mass Spectrometry Is Used in Proteomics?

Proteomics is a systematic science used to study all the expression, structure, and function of proteins. As an important analytical tool, mass spectrometry plays an indispensable role in proteomics research. In particular, Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS), due to its high sensitivity, high throughput, and high resolution, has become the mainstay of modern proteomics.

 

Mass spectrometry is a technique that analyzes based on the different ratios of mass and charge (m/z) of molecular ions. In the mass spectrometer, the sample goes through four steps: ionization, acceleration, deflection, and detection. The ion stream obtained can be converted into a mass spectrum. Each peak on the mass spectrum represents a specific m/z ratio, and the height of the peak indicates the ion intensity or abundance of that ratio.

 

Applications

Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) is based on liquid chromatography and further sends the obtained compounds into a mass spectrometer for analysis. The role of liquid chromatography is to separate complex samples, while mass spectrometry is to analyze the structure and quantitative analysis of single compounds. In proteomics research, LC-MS/MS technology mainly has the following applications:

 

1. Protein Identification

Through peptide fingerprint map matching and protein sequence data, the type of protein can be accurately identified.

 

2. Protein Quantification

Using labeling or label-free strategies, the expression level of proteins in different samples can be compared.

 

3. Protein Modification Analysis

Through in-depth analysis of peptide mass spectra, post-translational modifications such as phosphorylation and ubiquitination of proteins can be discovered.

 

4. Protein Interaction Network Analysis

Combined with techniques such as immunoprecipitation mass spectrometry, the interaction relationship between proteins can be revealed.