What Does Protein Mass Spectrometry Generally Measure?

Protein mass spectrometry detection is used to determine the mass, structure, and chemical modifications of proteins or polypeptides. Protein mass spectrometry detection is generally used for the following aspects:

 

1. Determination of Protein Mass

By determining the mass of protein molecules, we can understand the relative molecular mass of proteins, which helps in protein identification.

 

2. Determination of Protein Structure

By determining the structure of proteins, we can understand the secondary, tertiary and even quaternary structure of proteins, which helps in understanding the function of proteins.

 

3. Chemical Modification of Proteins

By determining the chemical modifications of proteins, such as phosphorylation, acetylation, etc., we can understand the active state and function of proteins.

 

4. Quantitative Analysis of Proteins

By determining the quantity of proteins, we can understand the relative content of proteins in the organism, which helps in understanding the function of proteins and the state of the organism.

 

Protein mass spectrometry detection, used for the analysis and identification of proteins and their complex mixtures, is typically used to measure the following key aspects:

 

1. Protein Identification

Through mass spectrometry technology, we can determine the types of proteins present in the sample. This is achieved through the analysis of the mass and fragmentation spectra of proteins or peptides, often matched with known databases to identify specific proteins.

 

2. Protein Quantification

Mass spectrometry technology can be used to quantitatively measure the expression level of proteins in the sample. This can be achieved through labelled (such as isotopic labelling) or label-free methods, helping researchers compare protein expression differences under different conditions.

 

3. Proteomic Analysis

By analyzing the collection of all proteins in a complex or sample (proteome), researchers can gain holistic information about the biological system.

 

4. Protein Modification

Mass spectrometry technology is very suitable for detecting post-translational modifications of proteins, such as phosphorylation, glycosylation, ubiquitination, etc. These chemical modifications have a significant impact on the function and intracellular localization of proteins.

 

5. Protein Structure Analysis

Although not as detailed as X-ray crystallography and nuclear magnetic resonance (NMR), mass spectrometry can also provide information about the secondary or tertiary structure of proteins, especially through cross-linking mass spectrometry technology.

 

6. Protein Interactions

By analyzing the composition and abundance of the components in the protein complex, mass spectrometry can help reveal the interactions between proteins.