Metal complexes of sulphur-containing amino acids

McAuliffe, Charles A.; Murray, Stephen G.

doi:10.1016/0073-8085(72)80013-5

Cited by 99 publications

(33 citation statements)

References 126 publications

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“…When GSH was included as a reductant, however, no damage could be detected. The reason for the superiority of cysteine over GSH is unclear but may derive from the ability of cysteine to form complexes with iron (31). In fact, the rate of iron reduction was not proportionate to cysteine concentration (data not shown), arguing against a simple rate-limiting electron transfer between cysteine and iron (see Discussion).…”

Section: Resultsmentioning

confidence: 89%

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High Levels of Intracellular Cysteine Promote Oxidative DNA Damage by Driving the Fenton Reaction

2003

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. However, when cells were cultured with poor sulfur sources and then exposed to cystine, they transiently exhibited a greatly increased susceptibility to H 2 O 2 , with <1% surviving the challenge. Cell death was due to an unusually rapid rate of DNA damage, as indicated by their filamentation, a high rate of mutation among the survivors, and DNA lesions by a direct assay. Cell-permeable iron chelators eliminated sensitivity, indicating that intracellular free iron mediated the conversion of H 2 O 2 into a hydroxyl radical, the direct effector of DNA damage. The cystine treatment caused a temporary loss of cysteine homeostasis, with intracellular pools increasing about eightfold. In vitro analysis demonstrated that cysteine reduces ferric iron with exceptional speed. This action permits free iron to redox cycle rapidly in the presence of H 2 O 2 , thereby augmenting the rate at which hydroxyl radicals are formed. During routine growth, cells maintain small cysteine pools, and cysteine is not a major contributor to DNA damage. Thus, the homeostatic control of cysteine levels is important in conferring resistance to oxidants. More generally, this study provides a new example of a situation in which the vulnerability of cells to oxidative DNA damage is strongly affected by their physiological state.

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Section: Resultsmentioning

confidence: 89%

“…It has been proposed that ferric iron might coordinate with the sulfhydryl and carboxylate groups of cysteine (50). McAuliffe and Murray suggested that the interaction of sulfur, iron, and oxygen atoms in a three-center system would promote facile electron transfer (31). The additional carboxylate group of GSH might disturb this geometry.…”

Section: Discussionmentioning

confidence: 99%

High Levels of Intracellular Cysteine Promote Oxidative DNA Damage by Driving the Fenton Reaction

2003

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“…XRD data for Ca-and Na-rich smectites suggest that cysteine is sorbed mostly on the external particle surface, whereas the amino acid is strongly retained in the interlayer by Cu-rich smectites. The increase in the d(001)-value may indicate the formation of a Cu-cysteine-complex in the interlayer sites (McAuliffe and Murray, 1972). Transition metal complexes of cysteine derivatives possessing monodentate coordination of the ligand through sulfur, bidentate coordination through sulfur and nitrogen (or oxygen), or tridentate coordination with sulfur, nitrogen, and oxygen atoms were previously studied (Aizawa et al, 1988).…”

Section: Na- Ca- and Cu-rich Smectite-cysteine Complexesmentioning

confidence: 99%

Effects of Exchange Cations and Layer-Charge Location on Cysteine Retention by Smectites

Brigatti

Lugli

Montorsi

et al. 1999

Clays and clay miner.

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Abstract--This study investigates the complexes formed between amino acids, which are the natural degradation products of organic matter, and smectites. Thus, the adsorption and desorption behavior of cysteine and Na-, Ca-, Cu-homoionic smectites with different layer-charge location, a montmorillonite, and a beidellite, were studied. The clay samples were treated with Na, Ca, and Cu 1 N solutions and then with a 0.2 M cysteine solution. To test smectite-cysteine stability at acidic pH, the solids obtained were repeatedly treated with distilled water acidified to pH = 5. All treated samples were characterized by thermal, X-ray diffraction, chemical, and infrared analyses. The results showed that: 1) Na-and Carich smectites adsorbed and retained small amounts of cysteine, and did not show interlayer cationcysteine complexes, whereas the amino acid was strongly retained in the interlayer by Cu-rich smectites; 2) d(001)-values for Na-and Ca-rich smectites showed little or no expansion, whereas for the Cu-rich smectites the intercalation of the organic molecule produced a swelling of the structure; 3) the interaction mechanism of homoionic smectites with cysteine in an aqueous medium occurs by weak interactions, (e.g., van der Waals interactions, hydrogen bonding, dipole-dipole interactions, and other electrostatic forces such as entropy-driven hydrophobic bonding), and/or by complexes involving interlayer cations and organic ligands. The formation of a stable chelate complex with the saturating ion permits cysteine to be adsorbed by Cu(II)-rich smectites and to be resistant to migration in soils and groundwaters.

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“…McAuliffe and Murray, 1972) have shown that in soluble ferric-cysteine complexes formed in alkaline media, the ligand coordinates to Fe via S-and CO0-groups, forming bidentate chelates; these groups should participate during cysteine adsorption on noncrystalline iron(III) hydroxide. Cysteine can, therefore, behave like other multi-dentate ligands (e.g., citrate, silicate, and maltose; Cornell, 1987), which at ratios ofL:Fe = 0.1 strongly retard the transformation of noncrystalline iron(III) hydroxide and, in addition, suppress the formation of goethite.…”

Section: Discussionmentioning

confidence: 99%

Effect of Cysteine and Manganese on the Crystallization of Noncrystalline Iron(III) Hydroxide at pH 8

Cornell

1990

Clays and clay miner.

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Abstract-To provide a greater understanding of the crystallization of iron oxides under natural aqueous conditions, the combined effect of an inorganic ion (in 2+) and a reducing organic ligand (L-cysteine) on the conversion of noncrystalline ferric hydroxide to goethite and/or hematite was investigated at pH 8.At cysteine: Fe ratios -> 0.2, L-cysteine caused noncrystalline iron(III) hydroxide to transform rapidly into goethite at pH 8; in the absence of the organic ligand, hematite was the predominant reaction product. The presence of Mn (>-9 mole %) in the cysteine-ferric hydroxide system retarded crystallization and reduced the goethite-promoting effect of cysteine.Polarographic measurements showed that the adsorption of cysteine on noncrystalline iron(III) hydroxide was immediately followed by the oxidation ofcysteine to the disulfide with simultaneous reduction of a proportion of the interracial ferric ions. The partly reduced noncrystalline iron(III) hydroxide dissolved at pH 8 more rapidly than the original material, thus facilitating the formation of goethite. In Mn(II)-noncrystalline iron(III) hydroxide coprecipitates, the interfacial oxidation/reduction reaction with cysteine (and hence the partial reduction of the noncrystalline phase) was reduced, due to replacement of some interfacial Fe(III) by non-reducible Mn.At pH 8, uptake of Mn by Clystalline iron oxides was low (< 5 mole %). Mn precipitated preferentially as pure Mn phases, either rhodochrosite (in NaHCO3 buffer) or hausmannite (in NH4C1/NH3 buffer).

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Metal complexes of sulphur-containing amino acids

Cited by 99 publications

References 126 publications

High Levels of Intracellular Cysteine Promote Oxidative DNA Damage by Driving the Fenton Reaction

High Levels of Intracellular Cysteine Promote Oxidative DNA Damage by Driving the Fenton Reaction

Effects of Exchange Cations and Layer-Charge Location on Cysteine Retention by Smectites

Effect of Cysteine and Manganese on the Crystallization of Noncrystalline Iron(III) Hydroxide at pH 8

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