Metallothionein I reduction of cytochrome c

Simpkins, Cuthbert O.; Eudaric, Philippe; Torrence, Cynthia A.; Yang, Zhen

doi:10.1016/0024-3205(93)90019-y

Cited by 14 publications

(4 citation statements)

References 8 publications

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“…It was earlier reported that Zn can inhibit mitochondrial electron transport [243] and also inhibit the oxidation of microsomally generated NADPH [244]. (Zn,Cd)MT has been shown to increase mitochondrial succinate-initiated oxygen uptake, inhibit ADP-stimulated oxygen uptake, and to facilitate the reduction of cytochrome c [240,241]. ZnMT has also been shown to increase the permeability of the inner mitochondrial membrane [245].…”

Section: Mt and Metabolismmentioning

confidence: 96%

“…A range of enzymes have been examined and shown to be inhibited by Zn at nanomolar concentrations and reactivated by addition of thionein [239]. For example, 150 nM Zn inhibited glyceraldehyde-3-phosphate dehydrogenase by 50%, and 200 nM thionein reactivated this enzyme by 90% in the presence of 1 mm Zn [240]. An influence on energy production by ATP binding to lysine residues on MT [237], as well as the modulation of mitochondrial respiration [240 -244], suggests a more central area of MT bioactivity.…”

Section: Mt and Metabolismmentioning

confidence: 99%

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Metallothionein: the multipurpose protein

Coyle¹,

Philcox²,

Lc³

et al. 2002

Cellular and Molecular Life Sciences (CMLS)

1,159

803

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Metallothioneins (MTs) are intracellular, low molecular, low molecular weight, cysteine-rich proteins. Ubiquitous in eukaryotes, MTs have unique structural characteristics to give potent metal-binding and redox capabilities. A primary role has not been identified, and remains elusive, as further functions continue to be discovered. The most widely expressed isoforms in mammals, MT-1 and MT-2, are rapidly induced in the liver by a wide range of metals, drugs and inflammatory mediators. In teh gut and pancreas, MT responds mainly to Zn status. A brain isoform, MT-3, has a specific neuronal growth inhibitory activity, while MT-1 and MT-2 have more diverse functions related to their thiolate cluster structure. These include involvement in Zn homeostasis, protection against heavy metal (especially Cd) and oxidant damage, and metabolic regulation via Zn donation, sequestration and/or redox control. Use of mice with altered gene expression has enhance our understanding of the multifaceted role of MT, emphasised in this review.

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Section: Mt and Metabolismmentioning

confidence: 96%

Section: Mt and Metabolismmentioning

confidence: 99%

Metallothionein: the multipurpose protein

Coyle¹,

Philcox²,

Lc³

et al. 2002

Cellular and Molecular Life Sciences (CMLS)

1,159

803

View full text Add to dashboard Cite

show abstract

“…Electron transfer has been observed between protein thiols and metal ions such as Cu 2+ and Fe 3+ . The reduction of metallothionine by a heme protein, cytochrome c, is thought to occur through a direct electron transfer from iron to cysteine [19], while other cysteine oxidation pathways in the presence of metal ions involve radical species. Cysteine residues are particularly susceptible to reactive oxygen species, such as superoxide and hydrogen peroxide, generated in the presence of redox-active metal ions.…”

Section: Role Of Cysteine Residues In the Reductase Activity Of Vanabin2mentioning

confidence: 99%

Role of cysteine residues in the V(V)-reductase activity of Vanabin2

Yamamoto

Matsuo

Michibata

et al. 2014

Inorganica Chimica Acta

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Ascidians (tunicates or sea squirts) accumulate extremely high levels of vanadium as the reduced form V(III) in extremely acidic vacuoles in their blood cells. Several key proteins related to vanadium accumulation have been isolated from vanadium-rich ascidians and their physiological functions characterized. Of these, vanabins are small, cysteine-rich proteins that have been identified only in vanadium-rich ascidians. Our previous study revealed that Vanabin2 can act as a V(V)-reductase. The current study examines the role of cysteine and several other amino acid residues of Vanabin2 in V(V)-reduction. When all eighteen cysteine residues of Vanabin2 were substituted with serine residues, the V(V)-reductase activity was lost. Substitutions of three, structurally clustered cysteines in three different regions resulted in a moderate decrease in reductase activity, suggesting that more than a single cysteine pair is responsible for the V(V)-reductase activity of Vanabin2. Mutations in the V(IV)-binding domains caused either an increase or decrease in activity but no mutation caused the complete 2 loss of activity. These results suggest that some pairs, but more than a single pair, of cysteine residues are necessary for the V(V)-reductase activity of Vanabin2.

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“…For the past 4 years our laboratory has been focused on the possible role that metallothionein plays in cytokine-mediated disease states such as sepsis [5,18]. A relationship between metallothionein and energy metabolism was supported by Rofe et al who showed that blood and liver concentrations of lactate were lower in metallothionein null MTϪ/Ϫ mice compared to normal MTϩ/ϩ mice given endotoxin [19].…”

Section: Discussionmentioning

confidence: 99%