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Consumer complaints against the blandness of modern lean meat and the frequent reference to the more strongly flavored meat that was available years ago have prompted reconsideration of high fat-depositing typical pig breeds. Casertana and Large White pig breeds are characterized by a different tendency toward fat accumulation as they exhibit opposite genetic and physiological traits with respect to the energy metabolism. These physiological differences were investigated in longissimus lumborum muscles through proteomics (2-DE, MS/MS) and microarray approaches. Data were analyzed for pathway and network analyses, as well as GO term enrichment of biological functions. As a result, Casertana showed a greater amount of proteins involved in glycolitic metabolism and mainly rely on fast-mobilizable energy sources. Large White overexpressed cell cycle and skeletal muscle growth related genes. Metabolic behavior and other implications are discussed.

Blue and colorless native gel electrophoresis in combination with LC-ESI-MS/MS are powerful tools in the analysis of protein networks in biological membranes. We used these techniques in the present study to generate a comprehensive overview on a proteome-wide scale of intracytoplasmic membrane (ICM) associated proteins in order to investigate the native supramolecular organization of Rhodobacter sphaeroides R26.1 photosynthetic apparatus. The results obtained were compared with past proteomic data, as well as with models for the topology of photosynthetic membranes as derived from previously published atomic force microscopy studies. We identified 52 proteins organized in 10 different multiprotein complexes. We were able to demonstrate the existence of different oligomeric states for the integral membrane pigment-protein complexes dedicated to bacterial photosynthesis. Specifically, we found dimers and trimers, as well as supercomplexes of light-harvesting (LH) 2 at very high molecular weights (around 10,000 kDa). We recovered the monomeric form of the photochemical reaction center (RC), as well as the monomer and dimer of the reaction center-light harvesting 1-PufX (RC-LH1-PufX) complex. Curiously, no type of LH1 complex was detected. Lastly, ATP synthase and cytochrome bc(1) complexes were only recovered in their monomeric states. Purified ICM vesicles were shown to be rich in newly discovered gene products, including three proteins with unknown functions (RSP_2125, RSP_3238, RSP_6207), a possible alkane hydroxylase and a spheroidene monooxygenase. Other multiprotein complexes were found to be localized in the ICM, including succinate dehydrogenase in trimeric form and sarcosine oxidase in two different aggregation states. These findings contribute to the growing body of evidence that the bacterial ICM is a specialized bioenergetic membrane hosting, not only photosynthesis, but many other critical activities.