title: An improvement on mass spectrometry-based epigenetic analysis of large histone-derived peptides by using the Ionization Variable Unit interface.
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.
authors.affiliation: Research and Development, Biosys Technologies, Meguro-Ku, Tokyo 152-0031, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Fukuda
authors.affiliation: AMR, Meguro-Ku, Tokyo 152-0031, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hike
authors.affiliation: AMR, Meguro-Ku, Tokyo 152-0031, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Usui
authors.affiliation: Research and Development, Biosys Technologies, Meguro-Ku, Tokyo 152-0031, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Bando
authors.affiliation: Research and Development, Biosys Technologies, Meguro-Ku, Tokyo 152-0031, Japan; Department of Measurement Technology and Electrical Engineering, Division of Clinical Protein Science and Imaging, Center of Excellence in Biological and Medical Mass Spectrometry (CEBMMS), Lund University Biomedical Center, SE-221 84 Lund, Sweden.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Nishimura
authors.affiliation: Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-Ku, Tokyo 153-8904, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kodama
authors.affiliation: Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-Ku, Tokyo 153-8904, Japan. Electronic address: kawamura@lsbm.org.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawamura
mesh_terms: D000595:Amino Acid Sequence; D044127:Epigenesis, Genetic; D006657:Histones / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D006657:Histones; D010446:Peptide Fragments
keywords: Charge state conversion; Collision-induced dissociation (CID); Epigenetics; Mass spectrometry; Multiply protonated peptides