Quantitative identification of protein nitration sites

Area of Science:

• Proteomics
• Chemical Biology
• Mass Spectrometry

Background:

• Post-translational modifications (PTMs) analysis is crucial in biological research.
• Quantification of specific PTMs like o-nitrotyrosine remains challenging.
• Existing iTRAQ chemistry is limited to primary amines.

Purpose of the Study:

• To develop a novel strategy for selective labeling and quantification of o-nitrotyrosine residues.
• To adapt iTRAQ chemistry for targeting o-nitrotyrosine.
• To enable simultaneous localization and quantification of protein nitration sites.

Main Methods:

• Utilized iTRAQ reagents for selective labeling of o-nitrotyrosine residues.
• Coupled iTRAQ labeling with Mass Spectrometry (MS) analysis.
• Applied the method to model proteins and biological systems.

Main Results:

• Successfully developed a new strategy for selective labeling of o-nitrotyrosine.
• Achieved simultaneous localization and quantification of nitration sites.
• Demonstrated the method's efficacy in both model proteins and biological samples.

Conclusions:

• The novel iTRAQ-based strategy effectively targets and quantifies o-nitrotyrosine residues.
• This method overcomes limitations of previous techniques for o-nitrotyrosine quantification.
• The approach facilitates comprehensive analysis of protein nitration in biological systems.