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Enzymatic characterization of five thioredoxins and a thioredoxin reductase from Myxococcus xanthus.
- Source :
-
FEMS microbiology letters [FEMS Microbiol Lett] 2024 Jan 09; Vol. 371. - Publication Year :
- 2024
-
Abstract
- Thioredoxin (Trx) is a disulfide-containing redox protein that functions as a disulfide oxidoreductase. Myxococcus xanthus contains five Trxs (Trx1-Trx5) and one Trx reductase (TrxR). Trxs typically have a CGPC active-site motif; however, M. xanthus Trxs have slightly different active-site sequences, with the exception of Trx4. The five Trxs of M. xanthus exhibited reduced activities against insulin, 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), cystine, glutathione disulfide (GSSG), S-nitrosoglutathione (GSNO), and H2O2 in the presence of TrxR. Myxococcus xanthus adenylate kinase and serine/threonine phosphatase activities, which were increased by the addition of dithiothreitol, were activated by the addition of Trxs and TrxR. Among these, Trx1, which has a CAPC sequence in its active site, exhibited the highest reducing activity with the exception of GSNO. Myxococcus xanthus TrxR showed weak reducing activity towards DTNB, GSSG, GSNO, and H2O2, suggesting that it has broad substrate specificity, unlike previously reported low-molecular-weight TrxRs. TrxR reduced oxidized Trx1 as the best substrate, with a kcat/Km value of 0.253 min-1 µM-1, which was 10-28-fold higher than that of the other Trxs. These results suggest that all Trxs possess reducing activity and that Trx1 may be the most functional in M. xanthus because TrxR most efficiently reduces oxidized Trx1.<br /> (© The Author(s) 2024. Published by Oxford University Press on behalf of FEMS.)
- Subjects :
- Substrate Specificity
Catalytic Domain
Bacterial Proteins metabolism
Bacterial Proteins genetics
Bacterial Proteins chemistry
Hydrogen Peroxide metabolism
Amino Acid Sequence
Myxococcus xanthus enzymology
Myxococcus xanthus genetics
Myxococcus xanthus metabolism
Thioredoxins metabolism
Thioredoxins chemistry
Thioredoxins genetics
Thioredoxin-Disulfide Reductase metabolism
Thioredoxin-Disulfide Reductase genetics
Thioredoxin-Disulfide Reductase chemistry
Oxidation-Reduction
Subjects
Details
- Language :
- English
- ISSN :
- 1574-6968
- Volume :
- 371
- Database :
- MEDLINE
- Journal :
- FEMS microbiology letters
- Publication Type :
- Academic Journal
- Accession number :
- 39038987
- Full Text :
- https://doi.org/10.1093/femsle/fnae058