Peptide identification from raw data was carried out using the MASCOT engine (Matrix Science, London, UK; version 2.2) and Proteome Discoverer software (Thermo Electron, San Jose, CA; version 1.4). The MS/MS spectra were searched against the UniProt sheep database (27,563 sequences, downloaded on 20/11/2021). The method for protein identification was referred as described previously (25 (link)). The following options were used: Peptide mass tolerance = 20 ppm, MS/MS tolerance = 0.1 Da, Enzyme = Trypsin, Missed cleavage = 2, Fixed modification: Carbamidomethyl (C), iTRAQ 8 plex (K), iTRAQ 8 plex (N-term), Variable modification: Oxidation (M) (25 (link)). Peptides were identified at a false discovery rate (FDR) ≤ 0.01. Differentially abundant proteins were determined using a Student's t-test. Proteins with P < 0.05 and a fold change ≥ 1.2 were considered upregulated, and a fold change ≤ 0.83 was considered to be downregulated.
Free full text: Click here