Full-text Article (Subscribers only)
Full-text article (426 kB)
(subscribers only)

Buy article on-line and get access immediately
Buy article on-line for £11.75
(get immediate access)

Search
Search

Go Back

Eur. J. Mass Spectrom. 2, 273 - 285 (1996)

An electrospray mass spectrometric study of organomercury(II) and mercuric interactions with peptides involving cysteinyl ligands

Antonella D'Agostino, Ray Colton and John C. Traeger
School of Chemistry, La Trobe University, Bundoora, Victoria 3083,Australia.
Allan J. Canty
Department of Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.

ABSTRACT:
Positive ion electrospray mass spectrometry (MS) has been used to investigate the interaction of Hg2+, [MeHg]+ and [PhHg]+ cations with cysteine (Cys), glutathione (GSH) and a 27-residue polypeptide (Pp) containing one cysteinyl sulfur located at the N-terminus. MS/MS experiments showed that organomercury adduction occurs primarily at the sulfhydryl group, with some evidence for isomeric species in which the organomercury cation is bound to either an amino or a carboxylic group. Following Ellman modification of GSH and Pp, the maximum number of adducted organomercury cations was reduced by 2 and 1, respectively, indicating a 2 : 1 and a 1 : 1 interaction between [RHg]+ and the cysteinyl sulfur. Unlike [PhHg]+, [MeHg]+ showed an almost exclusive affinity for the cysteinyl sulfur of GSH and Pp. Both Cys and GSH reacted with Hg2+ to form polynuclear species. Collisional activation mass spectra of the [2Cys + Hg H]+ ion indicated that the Hg(II) was most probably bridged between the two cysteinyl residues, although not necessarily via a conventional SHgS linkage.

Keywords:

You can now buy this paper on-line in PDF format; it costs only £11.75. Just click on the BUY on-line button. You can pay on-line through a secure server and get access immediately.


© IM Publications
Any problems? E-mail .