Mitochondria proteome profiling: A comparative analysis between gel- and gel-free approaches

Combining data retrieved from 2DE, 2D-LC and SDS-LC and search methods, a total of 696 non-redundant proteins were identified. An overlap of only 19% between the proteins identified by the three different methods was observed when Mascot and Paragon were used. Regarding protein ID, a consistency in the number of identified proteins per sample was noticed for 2DE approach. Independent of the methodological approach chosen, it was noticed that the predominance in mitochondria of hydrophilic proteins with 20-50 kDa and pI 5-6 and 8-9; however, 2D-LC and SDS-LC allowed the enrichment of proteins with a mass below 30 kDa and of basic proteins with pI values above 8. In conclusion, data from the present study highlight the power of integrating different separation technologies and protein identification algorithms.