Peak lists (MGF) were created in Mass Matrix Mass Spectrometric File Conversion Tools version 3.2. Peak lists were searched against Swiss–Prot and a decoy database using Mascot 2.3 . The following parameters were set for each search: tax- onomy was set to Homo sapiens; enzyme = trypsin; up to 3 missed cleavages; variable modifications: carbamidomethyl (C), deamidation (NQ), carboxy (E), oxidation (MKP); static modifications: none; peptide tolerance = 10 ppm; fragment tolerance = 0.5 Da; and pep- tide charge = 2+, 3+, 4+. Peptide results were filtered using Percolator at P < 0.05. Peptides with nonsensical post-translational modifications (e.g., carboxyglutamic acid [Gla] on non-Gla-containing proteins) were filtered by hand.