Metalloproteomic Profile Determination of Muscle Samples from Nile Tilapia (Oreochromis niloticus) Using AAS and ESI-MS/MS after 2D-PAGE Separation

This study evaluated the metalloproteomic profile of muscle tissue samples from Nile tilapia (Oreochromis niloticus). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) methods was used for protein fractionation and identification based on image analysis. Determination of Ca, Cu, Fe, Mn and Zn was performed in the protein spots by flame and/or graphite furnace atomic absorption spectrometry (FAAS, GFAAS), the protein spots were characterized by electrospray ionization-tandem mass spectrometry (ESI-MS/MS). FAAS and GFAAS determinations have indicated the presence of calcium in seven protein spots, iron in only one spot, manganese in six spots, and zinc in two spots. Of the seventeen protein spots where the presence of metal ions was detected, ten were characterized by ESI-MS/MS.