title: Hydrogen-deuterium exchange of α-carbon protons and fragmentation pathways in N-methylated glycine and alanine-containing peptides derivatized by quaternary ammonium salts.
abstract: Recently, we developed a selective and efficient method of hydrogen-deuterium exchange (HDX) at the α-carbon (α-C) of sarcosine residue (N-methylglycine) in model peptides [Bąchor et al. J. Mass Spectrom. 2014, 49, 43]. Here, we report the influence of quaternary ammonium (QA) group on HDX at the α-C of sarcosine and N-methylalanine in peptides. The obtained results suggest a significant acceleration of the HDX in sarcosine residue caused by the presence of QA. The effect depends on the distance between the sarcosine residue and QA moiety. The deuterons, introduced at α-C, are resistant to the back-exchange in acidic aqueous solution. The collision induced dissociation of the deuterium-labeled analogs of QA-tagged oligosarcosine peptides without mobile hydrogen revealed the mobilization of the hydrogens localized at α-C of sarcosine residue.
authors.affiliation: Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, Wroclaw, Poland.
authors.forename: Remigiusz
authors.initials: R
authors.lastname: Bąchor
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rudowska
authors.forename: Alicja
authors.initials: A
authors.lastname: Kluczyk
authors.forename: Piotr
authors.initials: P
authors.lastname: Stefanowicz
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Szewczuk
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D041961:Deuterium Exchange Measurement / Q000379:methods*; D007477:Ions / Q000032:analysis / Q000737:chemistry; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D011522:Protons; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012521:Sarcosine / Q000737:chemistry*
chemical_list: D007477:Ions; D010455:Peptides; D011522:Protons; D000644:Quaternary Ammonium Compounds; C008408:N-methylalanine; D002244:Carbon; D000409:Alanine; D012521:Sarcosine
keywords: ESI-MS/MS; HDX of peptides; charge-remote fragmentation; quaternary ammonium salts; sarcosine