Proteomic characterization of donkey milk “caseome”
2010
Chianese, Lina | Calabrese, Maria Grazia | Ferranti, Pasquale | Mauriello, Rosalba | Garro, Giuseppina | De Simone, Carmela | Quarto, Maria | Addeo, Francesco | Cosenza, Gianfranco | Ramunno, Luigi
At present, compared with bovine milk, the characterization of donkey milk caseins is at a relatively early stage progress, and only limited data are related to its genetic polymorphism. In this work, the heterogeneity of donkey caseome was investigated using a proteomic approach, based on one- (PAGE, UTLIEF) and two-dimensional (PAGE→UTLIEF) electrophoresis, stained with either Coomassie Brilliant Blue or specific polyclonal antibodies, and structural MS analysis. These combined methodologies allowed the contemporary identification of donkey αs₁, αs₂, β and κ-CN with their related heterogeneity due to phosphorylation (αs₁, αs₂ and β-CN), glycosylation (κ-CN) and incorrect splicing of RNA in mRNA (deleted forms of αs₁-CN and β-CN). The results achieved showed 11 components for κ-CN, six phosphorylated components for β and αs₁-CN and three main phosphorylated components for αs₂-CN, each accounting for 10, 11 and 12P/mole. At this regard, for the first time, the primary structure of the expressed protein corresponding to the only available donkey αs₂-CN cDNA sequence was determined. Furthermore β-CN was found in homozygous and heterozygous state for the occurrence of a genetic β-CN variant having a MW value 28 mass units higher than the common β-CN phenotype.
显示更多 [+] 显示较少 [-]