Plasmodium falciparum causes the deadliest form of malaria. Adequate redox control is crucial for this protozoan parasite to overcome oxidative and nitrosative challenges, thus enabling its survival. Sulfenylation is an oxidative post-translational modification, which acts as a molecular on/off switch, regulating protein activity. To obtain a better understanding of which proteins are redox regulated in malaria parasites, we established an optimized affinity capture protocol coupled with mass spectrometry analysis for identification of in vivo sulfenylated proteins. The non-dimedone based probe BCN-Bio1 shows reaction rates over 100-times that of commonly used dimedone-based probes, allowing for a rapid trapping of sulfenylated proteins. Mass spectrometry analysis of BCN-Bio1 labeled proteins revealed the first insight into the Plasmodium falciparum trophozoite sulfenylome, identifying 102 proteins containing 152 sulfenylation sites. Comparison with Plasmodium proteins modified by S-glutathionylation and S-nitrosation showed a high overlap, suggesting a common core of proteins undergoing redox regulation by multiple mechanisms. Furthermore, parasite proteins which were identified as targets for sulfenylation were also identified as being sulfenylated in other organisms, especially proteins of the glycolytic cycle. This study suggests that a number of Plasmodium proteins are subject to redox regulation and it provides a basis for further investigations into the exact structural and biochemical basis of regulation, and a deeper understanding of cross-talk between post-translational modifications.

恶性疟原虫会导致最致命的疟疾。充分的氧化还原控制对于这种原生动物寄生虫克服氧化和亚硝化挑战至关重要，从而使其得以生存。磺酰化是一种氧化翻译后修饰，它充当分子开/关开关，调节蛋白质活性。为了更好地了解哪些蛋白质在疟原虫中受到氧化还原调节，我们建立了优化的亲和捕获协议，并结合质谱分析进行体内鉴定亚磺酰化蛋白质。非二甲酮探针 BCN-Bio1 的反应速率是常用二甲酮探针的 100 倍以上，可快速捕获亚磺酰化蛋白质。BCN-Bio1 标记蛋白质的质谱分析揭示了对恶性疟原虫滋养体亚磺酰组的首次洞察，鉴定了含有 152 个亚磺酰化位点的 102 种蛋白质。与S-谷胱甘肽修饰和S修饰的疟原虫蛋白的比较-亚硝化表现出高度重叠，表明蛋白质的共同核心通过多种机制进行氧化还原调节。此外，被鉴定为亚磺酰化靶标的寄生虫蛋白也被鉴定为在其他生物体中被亚磺酰化，尤其是糖酵解循环的蛋白质。这项研究表明，许多疟原虫蛋白受到氧化还原调节，它为进一步研究调节的确切结构和生化基础以及更深入地了解翻译后修饰之间的串扰提供了基础。