title: A mechanistic study of the H/D exchange reactions of protonated arginine and arginine-containing di- and tripeptides.
abstract: The gas-phase H/D exchange reactions of arginine (R) and arginine-containing di- and tri-peptide (gly-arg (GR), arg-gly (RG), gly-gly-arg (GGR), gly-arg-gly (GRG) and arg-gly-gly (RGG)) [M + H]+ ions with deuterated ammonia (ND3) were investigated by using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR), ion mobility-mass spectrometry (IM-MS), ab initio and density functional theory-based molecular orbital calculations and molecular modeling. Three exchanges are observed for arginine and arginine-containing tri-peptide [M + H]+ ions, whereas the di-peptide [M + H]+ ions undergo a single H/D exchange. In addition, C-terminal methylation blocks H/D exchange of arginine and the arginine-containing peptide [M + H]+ ions, and a single H/D exchange is observed for N-terminal acetylated arginine [M + H]+ ions. A general mechanism for H/D exchange involving a collision complex that is best described as a "solvated salt-bridge" structure is proposed.
authors.affiliation: Department of Chemistry, The Laboratory for Biological Mass Spectrometry, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Huang
authors.forename: Joe A
authors.initials: JA
authors.lastname: Marini
authors.forename: John A
authors.initials: JA
authors.lastname: McLean
authors.forename: Shane E
authors.initials: SE
authors.lastname: Tichy
authors.forename: David H
authors.initials: DH
authors.lastname: Russell
mesh_terms: D000107:Acetylation; D001120:Arginine / Q000737:chemistry*; D017357:Cyclotrons; D041961:Deuterium Exchange Measurement; D005583:Fourier Analysis; D005740:Gases / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D008745:Methylation; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*; D044367:Phase Transition; D011522:Protons; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D005740:Gases; D009842:Oligopeptides; D011522:Protons; D006859:Hydrogen; C031918:glycyl-glycyl-argininal; D001120:Arginine