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Structures and fragmentations of Cobalt(II)–cysteine complexes in the gas phase
Author(s) -
Buchmann William,
Spezia Riccardo,
Tournois Guewen,
Cartailler Thierry,
Tortajada Jeanine
Publication year - 2007
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1183
Subject(s) - chemistry , cobalt , dissociation (chemistry) , cysteine , fragmentation (computing) , ion , sulfur , collision induced dissociation , mass spectrometry , medicinal chemistry , inorganic chemistry , organic chemistry , tandem mass spectrometry , chromatography , computer science , enzyme , operating system
The electronebulization of a cobalt(II)/cysteine(Cys) mixture in water/methanol (50/50) produced mainly cobalt‐cationized species. Three main groups of the Co‐cationized species can be distinguished in the ESI‐MS spectrum: (1) the cobalt complexes including the cysteine amino acid only (they can be singly charged, for example, [Co(Cys) n − H] + with n = 1–3 or doubly charged such as [Co + (Cys) 2 ] 2+ ); (2) the cobalt complexes with methanol: [Co(CH 3 OH) n − H] + with n = 1–3, [Co(CH 3 OH) 4 ] 2+ ; and (3) the complexes with the two different types of ligands: [Co(Cys)(CH 3 OH) − H] + . Only the singly charged complexes were observed. Collision‐induced dissociation (CID) products of the [Co(Cys) 2 ] 2+ , [Co(Cys) 2 − H] + and [Co(Cys) − H] + complexes were studied as a function of the collision energy, and mechanisms for the dissociation reactions are proposed. These were supported by the results of deuterium labelling experiments and by density functional theory calculations. Since [Co(Cys) − H] + was one of the main product ions obtained upon the CID of [Co(Cys) 2 ] 2+ and of [Co(Cys) 2 − H] + under low‐energy conditions, the fragmentation pathways of [Co(Cys) − H] + and the resulting product ion structures were studied in detail. The resulting product ion structures confirmed the high affinity of cobalt(II) for the sulfur atom of cysteine. Copyright © 2007 John Wiley & Sons, Ltd.