Transition metal ion induced deprotonation of amide hydrogens in sulfhydryl containing compounds

I. Sóvágó, R. Bruce Martin

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Three ligands that contain both amide and sulfhydryl groups were examined by an array of techniques for the capability of the sulfhydryl groups to serve as an anchor for Ni2+ or Pd2+ substitution for the amide hydrogen. α-Mercaptopropionylglycine serves as a terdendate ligand with a deprotonated and coordinated amide nitrogen from about pH 6-7 with Ni2+ and pH 3 with Pd2+. With both metal ions there is extensive polynuclear complex formation through sulfhydryl bridges in solutions containing comparable amounts of metal ion and ligand. With N-acetylcysteine neither Ni2- or Pd2+ induce amide hydrogen deprotonation at pH <12. Sulfhydryl bridging is again evident. With glutathione (GSH) sulfhydryl bridging provides a driving force for a switch from Ni2+ chelation at the γ-glutamyl locus to coordination at the sulfhydryl group in neutral or slightly basic solutions. Metal ion substitution for an amide hydrogen in glutathione only occurs at pH > 12 with Ni2+ and from pH 7 to 11 with Pd2+. It is suggested that in these GSH complexes the metal ion chelates the glycyl amide nitrogen and the sulfhydryl group in a six-membered ring.

Original languageEnglish
Pages (from-to)425-429
Number of pages5
JournalJournal of Inorganic and Nuclear Chemistry
Volume43
Issue number2
DOIs
Publication statusPublished - 1981

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Deprotonation
Amides
amides
Transition metals
Metal ions
Hydrogen
metal ions
transition metals
hydrogen
Ligands
ligands
Nitrogen
Acetylcysteine
Tiopronin
nitrogen
Anchors
chelates
Substitution reactions
substitutes
rings

Cite this

Transition metal ion induced deprotonation of amide hydrogens in sulfhydryl containing compounds. / Sóvágó, I.; Martin, R. Bruce.

In: Journal of Inorganic and Nuclear Chemistry, Vol. 43, No. 2, 1981, p. 425-429.

Research output: Contribution to journalArticle

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