Label-free based proteomics revealed the specific changes of muscle proteins in pike eel (Muraenesox cinereus) under cold stress

Chemical- and liquid chromatography coupled with mass spectrometry (LC–MS) based proteomics strategies were executed to investigate the alterations of protein profiles in pike eel (Muraenesox cinereus) muscle during chilling (CPE) and frozen (FPE) storage. Chemical results indicated that springiness and myofibrillar protein (MP) content of muscle tissues decreased significantly during 6 days of chilled and 120 days of frozen storage. LC–MS-based proteomics analysis suggested that great alterations occurred in muscle proteins mainly induced by cold stress. The differentially abundant proteins (DAPs) with low abundances in CPE and FPE samples included the annexins, fibronectin, ribosomal proteins, T-complex proteins, tubulin beta chain, and histones, which were mostly associated with the membrane structural constituents, cytoskeleton, and binding functional proteins. Results of eukaryotic cluster of orthologous group (KOG) verified that these identified DAPs were mainly converged in the cytoskeleton function resulting from cold conditions, which in turn affected the physical structure and chemical performances of muscle tissues.