2637-34-5Relevant articles and documents
Hydroperoxide and peroxynitrite reductase activity of poplar thioredoxin-dependent glutathione peroxidase 5: Kinetics, catalytic mechanism and oxidative inactivation
Selles, Benjamin,Hugo, Martin,Trujillo, Madia,Srivastava, Vaibhav,Wingsle, Gunnar,Jacquot, Jean-Pierre,Radi, Rafael,Rouhier, Nicolas
, p. 369 - 380 (2012)
Gpxs (glutathione peroxidases) constitute a family of peroxidases, including selenocysteine- or cysteine-containing isoforms (SeCys-Gpx or Cys-Gpx), which are regenerated by glutathione or Trxs (thioredoxins) respectively. In the present paper we show new data concerning the substrates of poplar Gpx5 and the residues involved in its catalytic mechanism. The present study establishes the capacity of this Cys-Gpx to reduce peroxynitrite with a catalytic efficiency of 106 M-1·s-1. In PtGpx5 (poplar Gpx5; Pt is Populus trichocarpa), Glu79, which replaces the glutamine residue usually found in the Gpx catalytic tetrad, is likely to be involved in substrate selectivity. Although the redox midpoint potential of the Cys44-Cys92 disulfide bond and the pKa of Cys44 are not modified in the E79Q variant, it exhibited significantly improved kinetic parameters (Kperoxide and kcat) with tert-butyl hydroperoxide. The characterization of the monomeric Y151R variant demonstrated that PtGpx5 is not an obligate homodimer. Also, we show that the conserved Phe90 is important for Trx recognition and that Trx-mediated recycling of PtGpx5 occurs via the formation of a transient disulfide bond between the Trx catalytic cysteine residue and the Gpx5 resolving cysteine residue. Finally, we demonstrate that the conformational changes observed during the transition from the reduced to the oxidized form of PtGpx5 are primarily determined by the oxidation of the peroxidatic cysteine into sulfenic acid. Also, MS analysis of in-vitro-oxidized PtGpx5 demonstrated that the peroxidatic cysteine residue can be over-oxidized into sulfinic or sulfonic acids. This suggests that some isoforms could have dual functions potentially acting as hydrogen-peroxide- and peroxynitrite- scavenging systems and/or as mediators of peroxide signalling as proposed for 2-Cys peroxiredoxins. The Authors Journal compilation
In situ formation of protein-polymer conjugates through reversible addition fragmentation chain transfer polymerization
Liu, Jingquan,Bulmus, Volga,Herlambang, David L.,Barner-Kowollik, Christopher,Stenzel, Martina H.,Davis, Thomas P.
, p. 3099 - 3103 (2007)
(Figure Presented) A good place for rafting: Bovine serum albumin (BSA) was site-specifically modified with a reversible addition fragmentation chain transfer (RAFT) agent and used in γ-radiation-initiated polymerization of oligo(ethylene glycol) acrylate. Well-defined polymer chains were formed at the RAFT agent conjugation site of BSA leading to the generation of BSA-polymer conjugates in situ.
Phosphodisulfide bond: A new linker for the oligonucleotide conjugation
Chassignol, Marcel,Thuong, Nguyen T.
, p. 8271 - 8274 (1998)
Oligonucleotide thiophosphates react with 2-pyridyl-disulfide derivatives to give phosphodisulfide which can, upon reduction, be easily cleaved to give the starting oligonucleotide with a terminal thiophosphate group.
Size-dependence of Fermi energy of gold nanoparticles loaded on titanium(iv) dioxide at photostationary state
Kiyonaga, Tomokazu,Fujii, Masashi,Akita, Tomoki,Kobayashi, Hisayoshi,Tada, Hiroaki
, p. 6553 - 6561 (2008)
TiO2 particle-supported Au nanoparticles (NPs) with varying sizes and good contact (Au/TiO2) were prepared under a constant loading amount by the deposition-precipitation method. The Fermi energy of Au NPs loaded on TiO2 a
Mass spectrometry-based assay for the rapid detection of thiol-containing natural products
Capehart, Stacy L.,Carlson, Erin E.
, p. 13229 - 13232 (2016)
Natural products are privileged scaffolds due to their high propensity to possess bioactivity. To expedite discovery of thiol-containing compounds, we devised a selective solid-supported reagent for their immobilization, followed by cleavage of a photocleavable linker to yield stable natural product conjugates for direct detection by mass spectrometry. Importantly, the natural products can also be tracelessly released to yield the native structures for chemical and biological evaluation.
The effect of nanometre-sized Au particle loading on TiO2 photocatalysed reduction of bis(2-dipyridyl)disulfide to 2-mercaptopyridine by H2O
Tada,Suzuki,Yoneda,Ito,Kobayashi
, p. 1376 - 1382 (2001)
TiO2 photocatalysed reduction of bis(2-dipyridyl)disulfide (RSSR) to 2-mercaptopyridine by H2O is enhanced significantly by incorporation of nanometre-sized Au particles. The rate is strongly dependent on the amount of Au loaded (x w
Integrated preparation method of 2-mercaptopyridine and 2, 2 '-pyridinium sulfide
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Paragraph 0037-0045, (2021/09/15)
The invention discloses an integrated preparation method of 2-mercaptopyridine and 2, 2 '-pyridinium sulfide, which comprises the steps of adding sulfur, sodium sulfide and a composite catalyst into water serving as a solvent, and uniformly stirring under a heating condition until the sulfur, the sodium sulfide and the composite catalyst are all dissolved; then adding 2-halogenated pyridine, and reacting for 20-30 hours at a reflux temperature, wherein the composite catalytic system is prepared by adding a cocatalyst with the same weight as cesium acetate into cesium acetate; after the reaction is finished, cooling the reaction liquid to the room temperature, then conducting extraction to respectively obtain extraction liquid and raffinate reaction liquid, and enabling the extraction liquid and the raffinate reaction liquid to be subjected to aftertreatment respectively to obtain 2, 2 '-pyridinium sulfide and 2-mercaptopyridine. The method can obtain two main products at the same time, and generation of by-products is reduced.
Promoting Effect of Crystal Water Leading to Catalyst-Free Synthesis of Heteroaryl Thioether from Heteroaryl Chloride, Sodium Thiosulfate Pentahydrate, and Alcohol
Ma, Xiantao,Yu, Jing,Yan, Ran,Yan, Mengli,Xu, Qing
supporting information, p. 11294 - 11300 (2019/09/12)
It is observed the crystal water in sodium thiosulfate pentahydrate (Na2S2O3·5H2O) can promote its multicomponent reaction with heteroaryl chlorides and alcohols, providing a facile, green, and specific synthesis of unsymmetrical heteroaryl thioethers via one-step formation of two C-S bonds under catalyst-, additive-, and solvent-free conditions. Mechanistic studies suggest that the crystal water in Na2S2O3·5H2O is crucial in generating the key thiol intermediates and byproduct NaHSO4, which then catalyzes the dehydrative substitution of alcohols with thiols to afford thioethers.
