32381-28-5Relevant articles and documents
Reaction of Nitroxyl (HNO) with Hydrogen Sulfide and Hydropersulfides
Zarenkiewicz, Jessica,Khodade, Vinayak S.,Toscano, John P.
, p. 868 - 877 (2021/01/14)
Nitroxyl (HNO) has gained a considerable amount of attention because of its promising pharmacological effects. The biochemical mechanisms of HNO activity are associated with the modification of regulatory thiol proteins. Recently, several studies have suggested that hydropersulfides (RSSH), presumed signaling products of hydrogen sulfide (H2S)-mediated thiol (RSH) modification, are additional potential targets of HNO. However, the interaction of HNO with reactive sulfur species beyond thiols remains relatively unexplored. Herein, we present characterization of HNO reactivity with H2S and RSSH. The reaction of H2S with HNO leads to the formation of hydrogen polysulfides and sulfur (S8), suggesting a potential role in sulfane sulfur homeostasis. Furthermore, we show that hydropersulfides are more efficient traps for HNO than their thiol counterparts. The reaction of HNO with RSSH at varied stoichiometries has been examined with the observed production of various dialkylpolysulfides (RSSnSR) and other nitrogen-containing dialkylpolysulfide species (RSS-NH-SnR). We do not observe evidence of sulfenylsulfinamide (RS-S(O)-NH2) formation, a pathway expected by analogy with the known reactivity of HNO with thiol.
Alkylamine-Substituted Perthiocarbamates: Dual Precursors to Hydropersulfide and Carbonyl Sulfide with Cardioprotective Actions
Khodade, Vinayak S.,Pharoah, Blaze M.,Paolocci, Nazareno,Toscano, John P.
supporting information, p. 4309 - 4316 (2020/03/05)
The recent discovery of hydropersulfides (RSSH) in mammalian systems suggests their potential roles in cell signaling. However, the exploration of RSSH biological significance is challenging due to their instability under physiological conditions. Herein, we report the preparation, RSSH-releasing properties, and cytoprotective nature of alkylamine-substituted perthiocarbamates. Triggered by a base-sensitive, self-immolative moiety, these precursors show efficient RSSH release and also demonstrate the ability to generate carbonyl sulfide (COS) in the presence of thiols. Using this dually reactive alkylamine-substituted perthiocarbamate platform, the generation of both RSSH and COS is tunable with respect to half-life, pH, and availability of thiols. Importantly, these precursors exhibit cytoprotective effects against hydrogen peroxide-mediated toxicity in H9c2 cells and cardioprotective effects against myocardial ischemic/reperfusion injury, indicating their potential application as new RSSH- and/or COS-releasing therapeutics.
“Doubly Orthogonal” Labeling of Peptides and Proteins
Tessier, Romain,Ceballos, Javier,Guidotti, Nora,Simonet-Davin, Raphael,Fierz, Beat,Waser, Jerome
supporting information, p. 2243 - 2263 (2019/08/08)
Herein, we report a cysteine bioconjugation methodology for the introduction of hypervalent iodine compounds onto biomolecules. Ethynylbenziodoxolones (EBXs) engage thiols in small organic molecules and cysteine-containing peptides and proteins in a fast and selective addition onto the alkynyl triple bond, resulting in stable vinylbenziodoxolone hypervalent iodine conjugates. The conjugation occurs at room temperature in an open flask under physiological conditions. The use of an azide-bearing EBX reagent enables a “doubly orthogonal” functionalization of the bioconjugate via strain-release-driven cycloaddition and Suzuki-Miyaura cross-coupling of the vinyl hypervalent iodine bond. We successfully applied the methodology on relevant and complex biomolecules, such as histone proteins. Through single-molecule experiments, we illustrated the potential of this doubly reactive bioconjugate by introducing a triplet-state quencher close to a fluorophore, which extended its lifetime by suppressing photobleaching. This work is therefore expected to find broad applications for peptide and protein functionalization. Understanding the molecular basis of life is essential in the search for new medicines. Chemical biology develops molecular tools for studying biological processes, setting the basis for new diagnostics and therapeutics, and relies heavily on the ability to selectively modify biomolecules. Two approaches have been especially fruitful: (1) selective modification of natural biomolecules and (2) selective reaction between non-natural functionalities in the presence of biomolecules (the so-called orthogonal bioconjugation). In our work, we contribute to both by transferring highly reactive hypervalent iodine reagents to cysteine residues in proteins and peptides. The obtained bioconjugates retain the reactive hypervalent bonds, which can be selectively functionalized via a metal-mediated reaction. Combined with a traditional azide tag, our approach allows a doubly orthogonal functionalization of biomolecules and is hence expected to be highly useful in chemical biology. Chemical biology develops molecular tools for studying biological processes, setting the basis for new diagnostics and therapeutics, and relies heavily on the ability to modify selectively biomolecules. In our work, we introduce hypervalent iodine bonds into peptides and proteins, via functionalization of cysteine, by using unique cyclic reagents developed in our group. The hypervalent bond can then be selectively modified in the presence of both natural and synthetic functional groups, opening new opportunities for applications in chemical biology.
