Kuo Yu-Hsuan, Konopko Aaron M, Borotto Nicholas B, Majmudar Jaimeen D, Haynes Sarah E, Martin Brent R
Program in Chemical Biology, Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA.
Chembiochem. 2017 Oct 18;18(20):2028-2032. doi: 10.1002/cbic.201700137. Epub 2017 Sep 1.
Cysteine residues are susceptible to oxidation to form S-sulfinyl (R-SO H) and S-sulfonyl (R-SO H) post-translational modifications. Here we present a simple bioconjugation strategy to label S-sulfinated proteins by using reporter-linked maleimides. After alkylation of free thiols with iodoacetamide, S-sulfinated cysteines react with maleimide to form a sulfone Michael adduct that remains stable under acidic conditions. Using this sequential alkylation strategy, we demonstrate differential S-sulfination across mouse tissue homogenates, as well as enhanced S-sulfination following pharmacological induction of endoplasmic reticulum stress, lipopolysaccharide stimulation, and inhibitors of the electron transport chain. Overall, this study reveals a broadened profile of maleimide reactivity across cysteine modifications, and outlines a simple method for profiling the physiological role of cysteine S-sulfination in disease.
半胱氨酸残基易于氧化，形成翻译后修饰的S-亚磺酰基（R-SO₂H）和S-磺酰基（R-SO₃H）。在此，我们提出一种简单的生物共轭策略，通过使用与报告基团相连的马来酰亚胺来标记S-亚磺酰化蛋白。在用碘乙酰胺对游离巯基进行烷基化后，S-亚磺酰化的半胱氨酸与马来酰亚胺反应形成砜迈克尔加合物，该加合物在酸性条件下保持稳定。使用这种顺序烷基化策略，我们证明了在小鼠组织匀浆中存在差异S-亚磺酰化，以及在内质网应激的药理学诱导、脂多糖刺激和电子传递链抑制剂作用后S-亚磺酰化增强。总体而言，本研究揭示了马来酰亚胺在半胱氨酸修饰中的反应性概况得到拓宽，并概述了一种简单的方法来分析半胱氨酸S-亚磺酰化在疾病中的生理作用。
