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.

蛋白质上的半胱氨酸残基可以与细胞氧化剂如过氧化氢反应。尽管此过程对于清除过量的活性氧非常重要，但这种氧化的产物也可能介导细胞信号转导。为了了解半胱氨酸氧化在生物学中的作用，需要使用选择性探针来检测和定量其发生。半胱氨酸氧化产物（例如亚磺酸）有时不稳定，因此寿命短。如果要分析此类半胱氨酸衍生物，则需要与探针快速反应。在这里，我们介绍降冰片烯衍生物作为半胱氨酸氧化的探针，并证明其捕获亚磺酸的能力。还报道了含有炔或生物素亲和标签的降冰片烯衍生物的合成，以促进这些探针在化学生物学和蛋白质组学中的使用。