An improvement on mass spectrometry-based epigenetic analysis of large histone-derived peptides by using the Ionization Variable Unit interface

Anal Biochem. 2015 Oct 1:486:14-6. doi: 10.1016/j.ab.2015.06.002. Epub 2015 Jun 5.

Abstract

Highly protonated histone-derived peptides impede a sufficient mass spectrometry (MS)-based epigenetic analysis because their relatively low m/z, due to a high degree of proton addition to peptides, would make it difficult to analyze the resulting complex MS/MS spectra. To reduce the degree of protonations, we have developed a new interface, the Ionization Variable Unit (IVU), in which peptides are ionized under a vaporized organic solvent. It is demonstrated that the doubly charged histone tail H2B peptide, PEPAKSAPAPKKGSKKAVTKAQKK (m/z 1238.243, +2), which was not detectable before, can be detected by using the IVU interface and sequenced.

Keywords: Charge state conversion; Collision-induced dissociation (CID); Epigenetics; Mass spectrometry; Multiply protonated peptides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Epigenesis, Genetic*
  • Histones / chemistry*
  • Molecular Sequence Data
  • Peptide Fragments / chemistry*
  • Tandem Mass Spectrometry / instrumentation
  • Tandem Mass Spectrometry / methods*

Substances

  • Histones
  • Peptide Fragments