The use of two-dimensional electrophoresis in the characterization of the water-soluble protein fraction of commercial flat fish species

7 páginas, 2 tablas, 4 figuras.-- The original publication is available at www.springerlink.comThe water-soluble proteins of nine flat fish species of high commercial value, belonging to the Pleuronectidae, Scophtalmidae, and Soleidae families, were analyzed by two-dimensional (2D) electrophoresis, this being carried out by nondenaturing isoelectric focusing (IEF) in the 3.5–9.5 pH range and gradient SDS-PAGE in the 12–14% range. Most of the major proteins fell in the 3.5–6.9 pH range. From these, the most specific proteins were in the acidic fraction (pI~5.2; MW~16 kDa). Species-specific 2D protein patterns were observed in all the nine species, and more than 25 proteins could be individualized. The combination of nondenaturing IEF and gradient SDSPAGE, both in the absence of urea, allowed detailed characterization of both the isoelectric points and molecular weights of the major water-soluble proteins and proved to be a valuable tool for the differential characterization of the flat fish species studied.The authors thank the financial support of CICYT (Project ALI95–0053).Peer reviewe