title: Fragmentation study of peptides using Fourier transform ion cyclotron resonance with infrared multiphoton dissociation: experiment and simulation.
abstract: In this study, the fragmentation of gas-phase protonated Angiotensin II is investigated using electrospray ionization (ESI), Fourier-transform ion cyclotron resonance (FT-ICR), and mass spectrometry (MS) with a laser cleavage infrared multiphoton dissociation (IRMPD) technique. The experimental results show that the spectra peaks for the photoproducts are y2/b6- and y7-type ions, corresponding to the cleavage of His-Pro and Asp-Arg in the parent amino acid sequence. The fragmentation of the peptide under collision-free vacuum conditions is modeled using molecular dynamics simulations (MD). The binding energy for the peptide bonds (C'-N bond) of Angiotensin II is estimated from ab initio calculations. The calculations are directed at predicting experimental measurements of the product ions from the photodissociation of the peptide. The product distributions simulated by the MD dissociation trajectories include predominantly y7/b1 and y2/b6 pair ions.
authors.affiliation: Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-41-6 Aomi, Koto-ku, Tokyo 135-0064, Japan. k-fukui@aist.go.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fukui
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Naito
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000804:Angiotensin II / Q000737:chemistry*; D003198:Computer Simulation; D010455:Peptides / Q000737:chemistry*; D017785:Photons; D020539:Sequence Analysis, Protein; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D010455:Peptides; D000804:Angiotensin II