Site-specific S-nitrosylation in Mouse Muscle Profiled by Cys-Enrichment Coupled with LC-MS/MS

摘要

1. The optimized resin - assisted cysteine - peptide enrichment approach for site - specific S- nitrosylation profiling provides comparable sensitivity and specificity for both peptide - and protein- level enrichment. 2. Quantitative reactivity profiling of S- nitrosylation in mouse muscle samples led to identification of a total 467 SNO sites from 197 proteins, and among them 275 Cys - sites from 142 proteins were revealed to be more sensitive to SNO modifications. 3. SNO- sensitive proteins appeared preferentially localized in mitochondria, contractile fiber, and actin cytoskeleton, which suggested the susceptibility of these subcellular compartments to redox regulation. 4. Many of the SNO- sensitive proteins are metabolic enzymes associated with TCA cycle, glycolysis/gluconeogenesis, glutathione metabolism, and fatty acid metabolism, highlighting the importance of redox regulation in metabolism. 5. A number of signaling proteins were also identified as SNO- sensitive proteins, suggesting the role of S - nitrosylation in signal transduction. 6. Discovery of the SNO- sensitive sites in mouse muscle would provide valuable information for understanding the nature of S- nitrosylation in cellular signaling pathways and in pathophysiology, such as insulin resistance.