Evidence for the fragmentation of VtgAb LvH in common dentex ( Dentex dentex), a marine pelagophil teleost

Abstract

Since the timing of the lipovitellin heavy chain (LvH) of vitellogenin Ab (VtgAb) degradation during marine teleosts ontogeny is poorly understood, the current study was planned to address some aspects of this shortcoming. Fertilized eggs (before epiboly) of Dentex dentex were analysed. Vtg-derived proteins, that appeared as 6 protein bands after SDS-PAGE, were purified using specific ion exchange chromatography. Five bands (i.e., ∼78, ∼57, ∼22, ∼19, and ∼17 kDa) were merely stained with Coomassie Blue and one band (i.e., ∼16 kDa) only with Periodic Acid Schiff (PAS). The ∼16 kDa protein band was subjected to a mass spectrometry-based sequencing. These results showed that the ∼16 kDa protein band contains a mixture of “LvH-Ab” derivatives with the same molecular weight. The specific staining system (i.e., PAS) also revealed the glycosylation of some of the LvH-Ab fragments inside the ∼16 kDa protein band. The study provides new data about fragmentation of the LvH-Ab in marine pelagophil teleosts.