S-Nitrosylated proteins in Saccharomyces cerevisiae were analyzed. S-Nitrosoglutathione was added to S. cerevisiae extract to induce S-nitrosylation. Thereafter, biotinylation was carried out by a biotin switch method, and pulldown was carried out by an avidin resin. After separation by SDS-PAGE, they were digested with trypsin and subjected to LC-MS.