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Norbornene derivatives were validated as probes for cysteine sulfenic acid on proteins and in live cells. Trapping sulfenic acids with norbornene probes is highly selective and revealed a different reactivity profile than the traditional dimedone reagent. The norbornene probe also revealed a superior chemoselectivity when compared to a commonly used dimedone probe. Together, these results advance the study of cysteine oxidation in biological systems.

Rapid detection of cysteine oxidation in living cells is critical in advancing our understanding of responses to reactive oxygen species (ROS) and oxidative stress. Accordingly, there is a need to develop chemical probes that facilitate proteome-wide detection of cysteine's many oxidation states. Herein, we report the first whole-cell proteomics analysis using a norbornene probe to detect the initial product of cysteine oxidation: cysteine sulfenic acid. The oxidised proteins identified in the HeLa cell model represent the first targets of the ROS hydrogen peroxide. The panel of protein hits provides new and important information about the targets of oxidative stress, including 148 new protein members of the sulfenome. These findings provide new leads for the study and understanding of redox signalling and diseases associated with oxidative stress.

© 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license http://creativecommons.org/licenses/by/4.0/)., Cysteine residues on proteins can react with cellular oxidants such as hydrogen peroxide. While this process is important for scavenging excess reactive oxygen species, the products of this oxidation may also mediate cell signalling. To understand the role of cysteine oxidation in biology, selective probes are required to detect and quantify its occurrence. Cysteine oxidation products such as sulfenic acids are sometimes unstable and therefore short-lived. If such cysteine derivatives are to be analysed, rapid reaction with the probe is required. Here we introduce norbornene derivatives as probes for cysteine oxidation, and demonstrate their ability to trap sulfenic acids. The synthesis of norbornene derivatives containing alkyne or biotin affinity tags are also reported to facilitate the use of these probes in chemical biology and proteomics.

Norbornene derivatives were validated as probes for cysteine sulfenic acid on proteins and in live cells. Trapping sulfenic acids with norbornene probes is highly selective and revealed a different reactivity profile than the traditional dimedone reagent. The norbornene probe also revealed a superior chemoselectivity when compared to a commonly used dimedone probe. Together, these results advance the study of cysteine oxidation in biological systems.

Powdered activated carbon (PAC) is an economical sorbent for removing micropollutants from water, but it generates hazardous dust that is flammable and a respiration hazard. Additionally, the fine particles of PAC can cake and block filters and membranes, complicating its use in continuous processes. In this study, we present a sulfur polymer support for PAC that overcomes these problems. The blend of the sulfur polymer and PAC generates low dust and it does not block filters. The utility of the sorbent is demonstrated in the remediation of water contaminated with perflurooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—persistent micropollutants that currently threaten water safety worldwide. Fundamental discoveries of PFOA self-assembly are also reported, as well as testing on a field sample of contaminated surface water. Refereed/Peer-reviewed