Dealkylation of organotin compounds by biological dithiols: toward the chemistry of organotin toxicity.
In this Communication, we report evidence for the dealkylation of trialkyltin compounds by a short linear peptide extracted from a small membrane protein (stannin) involved in cellular apoptosis and containing a CXC motif. We show that (a) organotin binding induces the formation of a beta-turn in the linear peptide, (b) both cysteines are necessary for the dealkylation reaction, and (c) stable 1:1 complexes are formed between the peptide and diorganotins that can be observed by ESI-MS. Organotin degradation by biological dithiols may be responsible for both the delayed activity of these toxins in humans and the organotin resistance mechanisms in bacteria.
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Bethany
B
Buck
Alessandro
A
Mascioni
Lawrence
L
Que
Gianluigi
G
Veglia
D000478:Alkylation; D002942:Circular Dichroism; D007700:Kinetics; D009479:Neuropeptides / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D014001:Tin / Q000737:chemistry*
D009479:Neuropeptides; D009842:Oligopeptides; D009942:Organometallic Compounds; D010446:Peptide Fragments; C075692:stannin; D014001:Tin