Predicting the stability of cyclic disulfides by molecular modeling: effective concentrations in thiol-disulfide interchange and the design of strongly reducing dithiols

Burns, John A.; Whitesides, George M.

doi:10.1021/ja00173a017

Cited by 118 publications

(109 citation statements)

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“…It is interesting to note, however, that activity with 2-mercaptoethanol or glutathione is not observed (12,17). This lack of activity is presumably a consequence of decreased reducing power and the inability to form a more stable intermolecular ring structure like DTT or the formation of a stable disulfide bond in thioredoxin (36)(37)(38)(39)(40)(41).…”

Section: Discussionmentioning

confidence: 99%

Thiol–disulfide exchange is involved in the catalytic mechanism of peptide methionine sulfoxide reductase

Lowther

Brot

Weissbach

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

162

183

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Peptide methionine sulfoxide reductase (MsrA; EC 1.8.4.6) reverses the inactivation of many proteins due to the oxidation of critical methionine residues by reducing methionine sulfoxide, Met(O), to methionine. MsrA activity is independent of bound metal and cofactors but does require reducing equivalents from either DTT or a thioredoxin-regenerating system. In an effort to understand these observations, the four cysteine residues of bovine MsrA were mutated to serine in a series of permutations. An analysis of the enzymatic activity of the variants and their free sulfhydryl states by mass spectrometry revealed that thioldisulfide exchange occurs during catalysis. In particular, the strictly conserved Cys-72 was found to be essential for activity and could form disulfide bonds, only upon incubation with substrate, with either Cys-218 or Cys-227, located at the C terminus. The significantly decreased activity of the Cys-218 and Cys-227 variants in the presence of thioredoxin suggested that these residues shuttle reducing equivalents from thioredoxin to the active site. A reaction mechanism based on the known reactivities of thiols with sulfoxides and the available data for MsrA was formulated. In this scheme, Cys-72 acts as a nucleophile and attacks the sulfur atom of the sulfoxide moiety, leading to the formation of a covalent, tetracoordinate intermediate. Collapse of the intermediate is facilitated by proton transfer and the concomitant attack of Cys-218 on Cys-72, leading to the formation of a disulfide bond. The active site is returned to the reduced state for another round of catalysis by a series of thiol-disulfide exchange reactions via Cys-227, DTT, or thioredoxin.oxidation ͉ cysteine ͉ thioredoxin ͉ Alzheimer's disease ͉ aging

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Section: Discussionmentioning

confidence: 99%

Thiol–disulfide exchange is involved in the catalytic mechanism of peptide methionine sulfoxide reductase

Lowther

Brot

Weissbach

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

162

183

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“…2A), and the L. pneumophila may well form an internal disulfide between residues corresponding to Ala 39 and Cys 43 in Grx4 ␣ 2 . However, it should be noted that oxidation of 3 cysteines, as in Grx4, is generally a three-step reaction where creation of an intramolecular disulfide via an unstable mixed disulfide intermediate involving two closely situated cysteines is followed by formation of a mixed disulfide on the third cysteine (44). Thus, the structural change on glutathione binding that allows for intradisulfide formation is likely to occur also in other monothiol glutaredoxins.…”

Section: Discussionmentioning

confidence: 99%

Molecular Mapping of Functionalities in the Solution Structure of Reduced Grx4, a Monothiol Glutaredoxin from Escherichia coli

Fladvad

Bellanda

Fernandes

et al. 2005

Journal of Biological Chemistry

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The ubiquitous glutaredoxin protein family is present in both prokaryotes and eukaryotes, and is closely related to the thioredoxins, which reduce their substrates using a dithiol mechanism as part of the cellular defense against oxidative stress. Recently identified monothiol glutaredoxins, which must use a different functional mechanism, appear to be essential in both Escherichia coli and yeast and are well conserved in higher order genomes. We have employed high resolution NMR to determine the three-dimensional solution structure of a monothiol glutaredoxin, the reduced E. coli Grx4. The Grx4 structure comprises a glutaredoxin-like ␣-␤ fold, founded on a limited set of strictly conserved and structurally critical residues. A tight hydrophobic core, together with a stringent set of secondary structure elements, is thus likely to be present in all monothiol glutaredoxins. A set of exposed and conserved residues form a surface region, implied in glutathione binding from a known structure of E. coli Grx3. The absence of glutaredoxin activity in E. coli Grx4 can be understood based on small but significant differences in the glutathione binding region, and through the lack of a conserved second GSH binding site. MALDI experiments suggest that disulfide formation on glutathionylation is accompanied by significant structural changes, in contrast with dithiol thioredoxins and glutaredoxins, where differences between oxidized and reduced forms are subtle and local. Structural and functional implications are discussed with particular emphasis on identifying common monothiol glutaredoxin properties in substrate specificity and ligand binding events, linking the thioredoxin and glutaredoxin systems.

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“…1 and also see Experimental). It was reported that MM2(85) calculations predicted a twist-boat-chair conformation for the parent 1,2-dithiocane [13] and, in addition, a similar conformation was observed for 1,2,5,6-tetrathiacyclooctanes in the solid state [14,15]. In analogy, 1,2-diselenocane (8) was assigned to be the trans isomer.…”

Section: Resultsmentioning

confidence: 78%

Reactions of sterically congested 1,6‐ and 1,7‐bis(diazo)alkanes with elemental sulfur and selenium: Formation of cyclohexene, 1,2‐dithiocane, 1,2‐diselenocane, and 1,2,3‐triselenecane derivatives

Ishii

Furusawa

Omata

et al. 2002

Heteroatom Chemistry

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Predicting the stability of cyclic disulfides by molecular modeling: effective concentrations in thiol-disulfide interchange and the design of strongly reducing dithiols

Cited by 118 publications

References 1 publication

Thiol–disulfide exchange is involved in the catalytic mechanism of peptide methionine sulfoxide reductase

Thiol–disulfide exchange is involved in the catalytic mechanism of peptide methionine sulfoxide reductase

Molecular Mapping of Functionalities in the Solution Structure of Reduced Grx4, a Monothiol Glutaredoxin from Escherichia coli

Reactions of sterically congested 1,6‐ and 1,7‐bis(diazo)alkanes with elemental sulfur and selenium: Formation of cyclohexene, 1,2‐dithiocane, 1,2‐diselenocane, and 1,2,3‐triselenecane derivatives

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