Data-Dependent Middle-Down ECD and CID Combined with Intact Protein Profiling for Histone Characterization using FT-ICR Mass Spectrometry

摘要

The feasibility of data-dependent middle-down ECD has been demonstrated. Extensive peptide sequence coverage was obtained in ECD, allowing confident peptide identification and localization of PTMs for histone analysis. Middle-down CID provided comparable results, although, for larger peptides ECD outperformed CID. High mass accuracy of both the precursor and product ions allowed differentiation between formylation and dimethylation. Middle-down ECD and CID were in agreement with the results obtained from intact protein profiling.