Mass spectrometric analysis of histone posttranslational modifications

Area of Science:

• Biochemistry
• Proteomics
• Mass Spectrometry

Background:

• Histones are crucial proteins involved in DNA packaging and gene regulation.
• Posttranslational modifications (PTMs) on histones significantly impact cellular processes.
• Accurate identification and quantification of histone PTMs are essential for understanding their functional roles.

Purpose of the Study:

• To describe the application of tandem mass spectrometry (MS/MS) and Fourier transform mass spectrometry (FTMS) for analyzing histone PTMs.
• To illustrate the utility of these mass spectrometry techniques with specific examples.
• To compare the information derived from intact protein sequencing versus proteolytic digestion strategies.

Main Methods:

• Utilizing tandem mass spectrometry (MS/MS) for peptide fragmentation and analysis.
• Employing Fourier transform mass spectrometry (FTMS) for high-resolution mass measurements.
• Comparing data obtained from analyzing intact histone proteins versus peptides generated by enzymatic digestion.

Main Results:

• Successful assignment of PTM sites and their occupancies on various histone proteins and isoforms.
• Demonstration of the complementary information provided by intact protein analysis and proteolytic digestion.
• Illustrative examples showcasing the power of MS/MS and FTMS in histone PTM characterization.

Conclusions:

• Tandem and Fourier transform mass spectrometry are powerful tools for comprehensive histone PTM analysis.
• Both intact protein sequencing and proteolytic digestion approaches offer valuable, yet distinct, insights into histone modifications.
• These methodologies advance our understanding of histone regulation and its impact on biological functions.