title: Angiotensin II-acetylcholine noncovalent complexes analyzed with MALDI-ion mobility-TOF MS.
abstract: Matrix-assisted laser desorption ionization-ion mobility-orthogonal time-of-flight mass spectrometry (MALDI-IM oTOF MS) is a new technique that allows laser desorbed ion to be preseparated on the basis of their shape prior to mas analysis. Using this instrument, we tested the postulate that addition of a quaternary ammonium compound such as acetylcholine to the model phosphorylated peptide angio tensin II would enhance its detection by MALDI in two ways. First of all, the acetylcholine-peptide complex could ionize more efficiently than the bare phosphopeptide. Furthermore the ion mobility could separate the complex ion on the basis of its charge/volume from isobaric interferences, which would otherwise limit detection sensitivity.
authors.affiliation: NIDA IRP, NIH, Baltimore, MD 21224, USA. awoods@intra.nida.nih.gov
authors.forename: Amina S
authors.initials: AS
authors.lastname: Woods
authors.forename: Katrin
authors.initials: K
authors.lastname: Fuhrer
authors.forename: Marc
authors.initials: M
authors.lastname: Gonin
authors.forename: Tom
authors.initials: T
authors.lastname: Egan
authors.forename: Michael
authors.initials: M
authors.lastname: Ugarov
authors.forename: Kent J
authors.initials: KJ
authors.lastname: Gillig
authors.forename: J Albert
authors.initials: JA
authors.lastname: Schultz
mesh_terms: D000109:Acetylcholine / Q000737:chemistry*; D000804:Angiotensin II / Q000737:chemistry*; D046911:Macromolecular Substances; D010766:Phosphorylation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013941:Thymine / Q000031:analogs & derivatives* / Q000737:chemistry; D014227:Triazines
chemical_list: D046911:Macromolecular Substances; D014227:Triazines; D000804:Angiotensin II; C005823:2-thio-6-azathymine; D000109:Acetylcholine; D013941:Thymine