Protein Sulfonic Acid Modification Detection

Protein sulfonic acid modification is a less common but very important kind of protein post-translational modifications. It involves the addition of a sulfate group to specific amino acid residues of a protein, usually tyrosine residues. Unlike phosphorylation, sulfonation is a covalent, permanent modification.

 

Common methods for detecting protein sulfonation include:

 

1. Mass Spectrometry (MS)

LC-MS/MS can be used to identify sulfonation sites due to the mass increase caused by sulfonation. However, sulfated peptides may lose the sulfate group in MS, making the identification challenging. The interpretation of MS data usually requires specific bioinformatics tools to ensure correct identification of sulfonation sites.

 

2. Western Blot with Sulfonation-Specific Antibodies

The sulfonation status can be detected using Western Blot method with specific antibodies against sulfated proteins or sulfonation sites.

 

3. Immunofluorescence Staining

Using sulfonation-specific antibodies, sulfated proteins can be located in cells or tissue slices through immunofluorescence staining.

 

4. Enzyme-Linked Immunosorbent Assay (ELISA)

An ELISA can be designed using sulfonation-specific antibodies for quantitative analysis of sulfated proteins.