Quantitative Proteomics Analysis by iTRAQ

The raw data were analyzed using LC MS/MS iTRAQ technology by ProteinPilot™ Software 4.5 (AB Sciex) [15 (link)–17 (link)]. Protein identification utilized the human SwissProt_2014_08. fasta sequence database. A standard parameter set was used for the search, which included Cys alkylation by methylmethanethiosulfonate (MMTS), biological modifications ID focus, trypsin digestion, Homo sapiens, search effort, and thorough ID. More than two unique peptides were required for protein identification. A threshold of confidence above 95% and a local FDR of less than 1% were used for both protein identification and quantitative analysis [23 (link)]. P-values < 0.05 were required for relative quantification.