title: In-Source Decay and Pseudo-MS3of Peptide and Protein Ions Using Liquid AP-MALDI.
abstract: Atmospheric pressure MALDI on a Q-Exactive instrument was optimized for in-source decay and pseudo-MS3. The dependence of AP-MALDI ISD on the MALDI liquid matrix was investigated for peptides and proteins. The liquid matrices enabled long-life ISD signal, and exhibited high fragment ion yield and signal stability. Extensive a-, b-, c-, y-, and z-type fragment series were observed depending on the matrix used but were most extensive with 2,5-DHB. Complete sequence coverage of small peptide and intact protein-terminus sequence tags were obtained and confirmed using HCD as a pseudo-MS3method. Graphical Abstract ᅟ.
authors.affiliation: Fondazione Pisana per la Scienza ONLUS, Pisa, Italy.
authors.forename: Rima
authors.initials: R
authors.lastname: Ait-Belkacem
authors.affiliation: Fondazione Pisana per la Scienza ONLUS, Pisa, Italy.|Dipartimento di Chimica e Chimica Industriale, University of Pisa, Pisa, Italy.
authors.forename: Marialaura
authors.initials: M
authors.lastname: Dilillo
authors.affiliation: Fondazione Pisana per la Scienza ONLUS, Pisa, Italy.|Scuola Normale Superiore di Pisa, Pisa, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Pellegrini
authors.affiliation: Fondazione Pisana per la Scienza ONLUS, Pisa, Italy.
authors.forename: Avinash
authors.initials: A
authors.lastname: Yadav
authors.affiliation: Fondazione Pisana per la Scienza ONLUS, Pisa, Italy.
authors.forename: Erik L
authors.initials: EL
authors.lastname: de Graaf
authors.affiliation: Fondazione Pisana per la Scienza ONLUS, Pisa, Italy. l.a.mcdonnell@lumc.nl.|Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands. l.a.mcdonnell@lumc.nl.|Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands. l.a.mcdonnell@lumc.nl.
authors.forename: Liam A
authors.initials: LA
authors.lastname: McDonnell
mesh_terms: D000595:Amino Acid Sequence; D007477:Ions; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007477:Ions; D010455:Peptides; D011506:Proteins
keywords: In-source decay; MALDI; MS/MS; Pseudo MS3; T3 sequencing