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Abstract The Sco protein fromThermus thermophilushas previously been shown to perform a disulfide bond reduction in the CuAprotein fromT. thermophilus, which is a soluble protein engineered from subunit II of cytochromeba3oxidase that lacks the transmembrane helix. The native cysteines onTtSco andTtCuAwere mutated to serine residues to probe the reactivities of the individual cysteines. Conjugation of TNB to the remaining cysteine inTtCuAand subsequent release upon incubation with the complementaryTtSco protein demonstrated the formation of the mixed disulfide intermediate. The cysteine ofTtSco that attacks the disulfide bond in the targetTtCuAprotein was determined to beTtSco Cysteine 49. This cysteine is likely more reactive than Cysteine 53 due to a higher degree of solvent exposure. Removal of the metal binding histidine, His 139, does not change MDI formation. However, altering the arginine adjacent to the reactive cysteine in Sco (Arginine 48) does alter the formation of the MDI. Binding of Cu2+or Cu+toTtSco prior to reaction withTtCuAwas found to preclude formation of the mixed disulfide intermediate. These results shed light on a mechanism of disulfide bond reduction by theTtSco protein and may point to a possible role of metal binding in regulating the activity. ImportanceThe function of Sco is at the center of many studies. The disulfide bond reduction in CuAby Sco is investigated herein and the effect of metal ions on the ability to reduce and form a mixed disulfide intermediate are also probed.
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This content will become publicly available on July 16, 2026
Adsorption and electron transfer of metal-reducing decaheme cytochrome protein MtrF on iron oxide nanoparticle surfaces
A simulation study reveals the adsorption behavior ofShewanellamultiheme cytochrome protein MtrF on small-sized α-Fe2O3nanoparticles in water and its electron transfer across the adsorbed protein.
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- PAR ID:
- 10618503
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Nanoscale
- Volume:
- 17
- Issue:
- 28
- ISSN:
- 2040-3364
- Page Range / eLocation ID:
- 16737 to 16747
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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