Here, we used a method, SNO trapping by triaryl phosphine (SNOTRAP), combined with mass spectrometry, to identify SNO-proteins present in post-mortem brain samples. Following analysis of SNO-proteins in samples of 11 human brains from patients LBD and controls, we detected 943 SNO-proteins and 1,552 SNO-sites, covering a wide range of the SNO proteome.