Nitrosylation Occupancy in the Myocardium With Cysteine- Reactive Tandem Mass Tags Short Communication

Snitrosylation (SNO) is a reversible, thiolbased modification that can modulate the activity of myocardial proteins, including those involved with Ca-handling and mitochondrial energetics. Additionally, we and others demonstrated that SNO can protect against cysteine oxidation. This is important in the setting of ischemia–reperfusion (IR) injury, in which the burst of reactive oxygen species generated at the onset of reperfusion can lead to protein oxidation and degradation. Myocardial ischemic preconditioning (IPC) has been shown to increase protein SNO, and thus protection from oxidation is expected to be proportionate to the percentage of protein SNO (ie, SNO occupancy). Therefore, it is important to develop a method to determine SNO occupancy.