title: Zundel-type H-bonding in biomolecular ions.
abstract: Using quantum chemical calculations and infrared multiphoton dissociation (IRMPD) spectroscopy in the fingerprint and X-H stretching regions, we demonstrate here that the all-Ala (b6) fragment ion features a macrocyclic structure with C(2) symmetry. For this structure, the ionizing proton is equally shared by the Ala(1) and Ala(4) amide oxygens in a Zundel-type symmetric (X…H(+)…X) H-bond.
authors.affiliation: Laboratoire de Chimie Physique, Université Paris Sud, UMR8000 CNRS, Faculté des Sciences, Bât. 350, 91405, Orsay Cedex, France.
authors.forename: Oscar
authors.initials: O
authors.lastname: Hernandez
authors.forename: Peter
authors.initials: P
authors.lastname: Pulay
authors.forename: Philippe
authors.initials: P
authors.lastname: Maître
authors.forename: Béla
authors.initials: B
authors.lastname: Paizs
mesh_terms: D000409:Alanine / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D006860:Hydrogen Bonding; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry; D008958:Models, Molecular; D010456:Peptides, Cyclic / Q000737:chemistry*; D011522:Protons; D013055:Spectrophotometry, Infrared
chemical_list: D000577:Amides; D007477:Ions; D010456:Peptides, Cyclic; D011522:Protons; D000409:Alanine