Accurate mass MS/MS/MS analysis of siderophores ferrioxamine B and E1 by collision-induced dissociation electrospray mass spectrometry.
Siderophores are bacterially secreted, small molecule iron chelators that facilitate the binding of insoluble iron (III) for reuptake and use in various biological processes. These compounds are classified by their iron (III) binding geometry, as dictated by subunit composition and include groups such as the trihydroxamates (hexadentate ligand) and catecholates (bidentate). Small modifications to the core structure such as acetylation, lipid tail addition, or cyclization, make facile characterization of new siderophores difficult by molecular ion detection alone (MS(1)). We have expanded upon previous fragmentation-directed studies using electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS/MS) and identified diagnostic MS(3) features from the trihydroxamate siderophore class for ferrioxamine B and E1 by accurate mass. Diagnostic features for MS(3) include C-C, C-N, amide, and oxime cleavage events with proposed losses of water and -CO from the iron (III) coordination sites. These insights will facilitate the discovery of novel trihydroxamate siderophores from complex sample matrices. Graphical Abstract ᅟ.
Department of Chemistry, Indiana University, Bloomington, IN, 47403, USA.
Ashley M
AM
Sidebottom
Department of Chemistry, Indiana University, Bloomington, IN, 47403, USA.
Jonathan A
JA
Karty
Department of Chemistry, Indiana University, Bloomington, IN, 47403, USA. carlsone@umn.edu.|Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47403, USA. carlsone@umn.edu.|Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA. carlsone@umn.edu.
Erin E
EE
Carlson
D003676:Deferoxamine / Q000032:analysis / Q000737:chemistry*; D005290:Ferric Compounds / Q000032:analysis / Q000737:chemistry*; D008958:Models, Molecular; D010456:Peptides, Cyclic / Q000032:analysis / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D005290:Ferric Compounds; D010456:Peptides, Cyclic; C017508:ferrioxamine E; C002577:ferrioxamine B; D003676:Deferoxamine
Accurate mass; MS/MS/MS; Siderophore; Trihydroxamate