Differential reactivity of the functional sulfhydryl groups of cysteine-32 and cysteine-35 present in the reduced form of thioredoxin from Escherichia coli.

Kallis, G.B.; Holmgren, Arne

doi:10.1016/s0021-9258(19)70458-x

Cited by 358 publications

(163 citation statements)

References 20 publications

Supporting

Mentioning

141

Contrasting

Order By: Relevance

“…Indeed, a cysteine at the N terminus of any helix is highly favoured as a result of the interaction with the helix dipole [35] and leads to a reduction in the cysteine pK a compared with the normal value (~9). All four of the thioredoxin family of redox proteins exhibit a reduced pK a for this cysteine, although the pK a of ~6-7 for thioredoxin [36][37][38] is somewhat higher than the pK a values of 3.5-4.5 measured for DsbA [17,18], glutaredoxin [39][40][41] and PDI [19].…”

Section: Discussionmentioning

confidence: 70%

Crystal structures of reduced and oxidized DsbA: investigation of domain motion and thiolate stabilization

1998

View full text Add to dashboard Cite

The structures of reduced and oxidized DsbA reveal that hinge bending motions do occur between the two domains. These motions are independent of redox state, however, and therefore do not contribute to the energetic differences between the two redox states. Instead, the observed domain motion is proposed to be a consequence of substrate binding. Furthermore, DsbA's highly oxidizing nature is a result of hydrogen bond, electrostatic and helix-dipole interactions that favour the thiolate over the disulfide at the active site.

show abstract

Section: Discussionmentioning

confidence: 70%

Crystal structures of reduced and oxidized DsbA: investigation of domain motion and thiolate stabilization

1998

View full text Add to dashboard Cite

show abstract

“…beled with two PEG-PCMal. Since Cys32 of EcTrxA corresponding to Cys33 of PsTrxA has a lower pKa and is more reactive [29], the thiol group of Cys33 might attack selenite nucleophilically to produce a thioselenite moiety (-S-SeO2 − ) as previously suggested [26], then the thiol group would not be labeled with PEG-PCMal. The lower bands were also observed in C33A and C33A/C36A incubated with selenite followed by PEG-PCMal labeling.…”

Section: Number Of Free Thiols In Pstrxa Incubated With Selenitementioning

confidence: 93%

Initial Step of Selenite Reduction via Thioredoxin for Bacterial Selenoprotein Biosynthesis

Shimizu

Tobe

Aono

et al. 2021

IJMS

View full text Add to dashboard Cite

Many organisms reductively assimilate selenite to synthesize selenoprotein. Although the thioredoxin system, consisting of thioredoxin 1 (TrxA) and thioredoxin reductase with NADPH, can reduce selenite and is considered to facilitate selenite assimilation, the detailed mechanism remains obscure. Here, we show that selenite was reduced by the thioredoxin system from Pseudomonas stutzeri only in the presence of the TrxA (PsTrxA), and this system was specific to selenite among the oxyanions examined. Mutational analysis revealed that Cys33 and Cys36 residues in PsTrxA are important for selenite reduction. Free thiol-labeling assays suggested that Cys33 is more reactive than Cys36. Mass spectrometry analysis suggested that PsTrxA reduces selenite via PsTrxA-SeO intermediate formation. Furthermore, an in vivo formate dehydrogenase activity assay in Escherichia coli with a gene disruption suggested that TrxA is important for selenoprotein biosynthesis. The introduction of PsTrxA complemented the effects of TrxA disruption in E. coli cells, only when PsTrxA contained Cys33 and Cys36. Based on these results, we proposed the early steps of the link between selenite and selenoprotein biosynthesis via the formation of TrxA–selenium complexes.

show abstract

“…producing a mixed disulfide intermediate (that is, an intermediate containing an intermolecular disulfide bond), followed by attack of the thiolate of Cys35 (pKa -7.5-8.6 in hTRX [30]) to yield a reduced substrate and oxidized thioredoxin [31]. We therefore trapped a kinetically stable mixed disulfide intermediate (that is an intermediate containing an intermolecular disulfide bond) of hTRX and the NFKB peptide using the quadruple Cys--Ala mutant (C35A, C62A, C69A and C73A) of hTRX which retains the reactive Cys32.…”

Section: Current Biology Ltd Issn 0969-2126 289mentioning

confidence: 99%

Solution structure of human thioredoxin in a mixed disulfide intermediate complex with its target peptide from the transcription factor NFκB

et al. 1995

View full text Add to dashboard Cite

In addition to the intermolecular disulfide bridge between Cys32 of human thioredoxin and Cys62 of the peptide, the complex is stabilized by numerous hydrogen-bonding, electrostatic and hydrophobic interactions which involve residues 57-65 of the NF kappa B peptide and confer substrate specificity. These structural features permit one to suggest the specificity requirements for human thioredoxin-catalyzed disulfide bond reduction of proteins.

show abstract

Differential reactivity of the functional sulfhydryl groups of cysteine-32 and cysteine-35 present in the reduced form of thioredoxin from Escherichia coli.

Cited by 358 publications

References 20 publications

Crystal structures of reduced and oxidized DsbA: investigation of domain motion and thiolate stabilization

Crystal structures of reduced and oxidized DsbA: investigation of domain motion and thiolate stabilization

Initial Step of Selenite Reduction via Thioredoxin for Bacterial Selenoprotein Biosynthesis

Solution structure of human thioredoxin in a mixed disulfide intermediate complex with its target peptide from the transcription factor NFκB

Contact Info

Product

Resources

About