“…These excised gels were destained with destaining solution containing 15 mmol/L potassium hexacyanoferrate (III) (Wako, Osaka, Japan) and 50 mmol/L sodium thiosulfate (Sigma, St Louis, Mo) and digested with sequencing-grade modified trypsin (Promega, Madison, Wis), and using these peptide extracts, we performed nano-HPLC sample separation with a Paradigm MS4 LC system (Michrom BioResources, Auburn, Calif) 14 and MALDI-TOF/TOF mass spectrometry with ultraflex II (BRUKER Daltonics, Billerica, Mass). 13 Molecular mass information obtained by MALDI-TOF/ TOF mass spectrometry was searched against the Swiss-Prot protein database (version 56.5, http://www.expasy.org/sprot/) with the MASCOT search program (version 2.2; MatrixScience, Boston, Mass) automatically using the Warp-LC software (BURUKER Daltnics), which attached to the ultraflex II. The following search criteria were used: (1) the taxonomy was Homo sapiens (human being); (2) the specified enzyme was trypsin, with up to 1 missed cleavage permitted; (3) the fixed modifications were carbamidomethylation of cysteine residues and variable modifications were oxidation of methionine residues; and (4) the peptide tolerance and MS/MS tolerance were set at 100 ppm and 6 0.5 d, respectively.…”