IPG with electrodic plateaus (and other unusual procedures for 2-DE).
ABSTRACT We describe some simple changes to the geometry of the IPG strips that make them suitable to the loading of very large sample volumes and of high-salt solutions. Of special relevance is the possibility of using strips with immobilized plateau(s) to either side of the gradient, or to both, also in connection with in-gel rehydration protocols and focusing in stock trays. The only requirement to achieve this is to leave the all-ready-made attitude and go back to custom polymerization of the IPGs in one's laboratory.
Article: Immobilized pH gradients.[Show abstract] [Hide abstract]
ABSTRACT: In this short review, we give an account of the steps through which the protocols for operation with IPGs were set up in the early '80s. One of the main achievements by our group was the development of a computer program, pH GRADIENT, for the calculation of pH, buffering power and ionic strength of a mixture of monoprotic buffers titrated within any pH span and for the linearization of the desired pH gradient. Using this program, in 1984 we could devise formulations for IPGs covering up to six pH units, which was the subject of a publication in Electrophoresis (volume 5, pages 88-97). This was the starting point for the use of IPGs for the resolution of protein samples of any composition and for their application as first dimension of 2-DE separations. Currently IPGs are in common use in proteomics investigations, not only along classical protocols but also for sample prefractionation and in shotgun approaches. Much less frequently are they used for 1-DE analytical applications, a field for which in recent years much attention has instead more often focused on capillary electrophoresis/IEF procedures.Electrophoresis 07/2009; 30 Suppl 1:S112-21. · 3.26 Impact Factor
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ABSTRACT: We describe the characterization of polyclonal antibodies directed against the whole mitochondrial subproteome, as obtained by hyperimmunization of rabbits with an organelle fraction purified from human skeletal muscle and lysed by sonication. After 2-DE separations with either blue native electrophoresis or IPG as first dimension and blotting, the polyspecific antibodies detect 113 proteins in human muscle mitochondria, representative of all major biochemical pathways and oxidative phosphorylation (OXPHOS) complexes, and cross-react with 28 proteins in rat heart mitochondria. Using as sample cryosections of human muscle biopsies lysed in urea/thiourea/CHAPS, the mitochondrial subproteome can be detected against the background of contractile proteins. When comparing with controls samples from mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes patients, immunoblotting shows in the latter a drastic reduction for the subunits of OXPHOS complex I as well as an increase of several enzymes, including ATP synthase. This finding is the first evidence at the proteomic level of massive up-regulation in a number of metabolic pathways by which the affected tissues try to compensate for the deficit in the OXPHOS machinery.Electrophoresis 05/2009; 30(8):1329-41. · 3.26 Impact Factor
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ABSTRACT: More than a decade ago our groups pioneered the analysis of serum proteins of laboratory animals with up-to-date proteomic techniques. We were, and still are, convinced that conforming animal procedures to the minimally invasive approaches typical of clinical biochemistry focuses attention on the actual conditions under which any finding arrived at on animal models of disease may eventually be applied to human patients for screening/diagnosis. We are also convinced that, besides the proteins present in trace level as a result of tissue leakage during disorders affecting specific peripheral organs, changes in the concentration of some of the major serum proteins as part of an acute-phase response may be taken as biological end-points during a number of experimental procedures. When reviewing literature data about proteomic investigations on plasma or serum of mice, we realized that not much work has been done in the direction we favor. In addition, we noticed that sometimes information about serum proteome has been coarsely treated and in a few cases even misunderstood/misused. In the following, we present current findings on serum/plasma proteome of the laboratory mouse not only under control conditions and during an experimentally induced acute-phase reaction, but also in a number of models of disease, mainly related to cancer and to metabolic disorders.Proteomics 01/2012; 12(4-5):691-707. · 4.43 Impact Factor