Changes in protein composition of epidermal mucus in turbot Scophthalmus maximus (L.) under high water temperature

To explore the skin mucous of juvenile turbot (Scophthalmus maximus) protein under thermo-treatment in different temperatures (20, 23, 25, and 27 °C), the corresponding proteome maps were constructed by two-dimensional gel electrophoresis (2-DE), from which the peptide mass map with MALDI-TOF-TOF was obtained, and a novel protein of polypeptide was identified by database retrieval. Results show that the proteome maps varied remarkably with temperature, indicating the increase or decrease in protein spot. Totally, 209 protein spots were matched in five maps in temperature using ImageMaster 2D Platinum 6.0. In addition, six unique protein spots were selected and identified with MALDI-TOF-TOF. By searching database for protein identification and function prediction, five proteins were confirmed, of which lectin and cytokeratin are highly potential as protein marker for further research. The information should be useful for better understanding the role of mucus as a component of innate immune system and for identifying genotypes that suit best to the aquiculture environment. These proteins could be used as potential biomarkers to environmental stressors in mucus for providing early warning when fish suffers in a dangerous situation.