Article

How to analyze protein complexes by 2D blue native SDS-PAGE.

Ludwig Maximilian University, Munich, Germany.
Proteomics (Impact Factor: 4.43). 10/2007; 7 Suppl 1:6-16. DOI: 10.1002/pmic.200700205
Source: PubMed

ABSTRACT Natural compartmentalization makes proteome analysis of the cell, cell organelles and organelle subfractions possible. Protein complexes are the basis for the next level of compartmentalization that can be addressed well with proteomic technology. Protein complexes organize and maintain the cellular and organelle functions on all levels of complexity in time and space. Cell development and division, transcription and translation, respiration and photosynthesis, transport and metabolism can be defined by the activity of protein complexes. Since a large part of the protein complexes of the cell body are inserted in lipid membrane phases, isolation, separation and protein subunit identification were difficult to address. Blue native polyacrylamide gel electrophoresis (BN-PAGE) provides us with the technology for high resolution separation of membrane protein complexes. Here, we show that high resolution separation of protein complexes by BN-PAGE requires the establishment of a detailed solubilisation strategy. We show that BN/SDS-PAGE provides the scientist with a high resolution array of protein subunits which allows analysis of the specific subunit stoichiometry of a protein complex as well as the assembly of protein complexes by standard protein detection methodology like DIGE, gelblot analysis and mass spectrometry. We envision BN-PAGE to precede classical 2D IEF/SDS-analysis for detailed characterization of membrane proteomes.

2 Bookmarks
 · 
277 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tight junctions are multiprotein complexes that form the fundamental physiologic and anatomic barrier between epithelial and endothelial cells, yet little information is available about their molecular organization. To begin to understand how the transmembrane proteins of the tight junction are organized into multiprotein complexes, we used blue native-PAGE (BN-PAGE) and cross-linking techniques to identify complexes extracted from MDCK II cells and mouse liver. In nonionic detergent extracts from MDCK II cells, the tight junction integral membrane protein claudin-2 was preferentially isolated as a homodimer, whereas claudin-4 was monomeric. Analysis of the interactions between chimeras of claudin-2 and -4 are consistent with the transmembrane domains of claudin-2 being responsible for dimerization, and mutational analysis followed by cross-linking indicated that the second transmembrane domains were arranged in close proximity in homodimers. BN-PAGE of mouse liver membrane identified a relatively discrete high molecular weight complex containing at least claudin-1, claudin-2, and occludin; the difference in the protein complex sizes between cultured cells and tissues may reflect differences in tight junction protein or lipid composition or post-translational modifications. Our results suggest that BN-PAGE may be a useful tool in understanding tight junction structure.
    Journal of Biological Chemistry 02/2011; 286(5):3442-50. · 4.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Helicobacter pylori infection plays a causal role in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma (LG-MALT) and duodenal ulcer (DU). Although many virulence factors have been associated with DU, many questions remain unanswered regarding the evolution of the infection toward this exceptional event, LG-MALT. The present study describes and compares the complexome of two H. pylori strains, strain J99 associated with DU and strain B38 associated with LG-MALT, using the two-dimensional blue native/SDS-PAGE method. It was possible to identify 90 different complexes (49 and 41 in the B38 and J99 strains, respectively); 12 of these complexes were common to both strains (seven and five in the membrane and cytoplasm, respectively), reflecting the variability of H. pylori strains. The 44 membrane complexes included numerous outer membrane proteins, such as the major adhesins BabA and SabA retrieved from a complex in the B38 strain, and also proteins from the hor family rarely studied. BabA and BabB adhesins were found to interact independently with HopM/N in the B38 and J99 strains, respectively. The 46 cytosolic complexes essentially comprised proteins involved in H. pylori physiology. Some orphan proteins were retrieved from heterooligomeric complexes, and a function could be proposed for a number of them via the identification of their partners, such as JHP0119, which may be involved in the flagellar function. Overall, this study gave new insights into the membrane and cytoplasm structure, and those which could help in the design of molecules for vaccine and/or antimicrobial agent development are highlighted.
    Molecular &amp Cellular Proteomics 12/2010; 9(12):2796-826. · 7.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of the present study was to analyze serum protein complexes and detect serum esterase activities using nongradient blue native polyacrylamide gel electrophoresis (BN-PAGE). For analysis of potential protein complexes, serum from rat was used. Results demonstrate that a total of 8 gel bands could be clearly distinguished after Coomassie blue staining, and serum albumin could be isolated nearly as a pure protein. Moreover, proteins in these bands were identified by electrospray mass spectrometry and low-energy collision induced dissociation (CID)-MS/MS peptide sequencing and the existence of serum dihydrolipoamide dehydrogenase (DLDH) was confirmed. For studies of in-gel detection of esterase activities, serum from rat, mouse, and human was used. In-gel staining of esterase activity was achieved by the use of either α-naphthylacetate or β-naphthylacetate in the presence of Fast blue BB salt. There were three bands exhibiting esterase activities in the serum of both rat and mouse. In contrast, there was only one band showing esterase activity staining in the human serum. When serum samples were treated with varying concentrations of urea, esterase activity staining was abolished for all the bands except the one containing esterase 1 (Es1) protein that is known to be a single polypeptide enzyme, indicating that majority of these esterases were protein complexes or multimeric proteins. We also identified the human serum esterase as butyrylcholinesterase following isolation and partial purification using ammonium sulfate fractioning and ion exchange column chromatographies. Where applicable, demonstrations of the gel-based method for measuring serum esterase activities under physiological or pathophysiological conditions were illustrated. Results of the present study demonstrate that nongradient BN-PAGE can serve as a feasible analytical tool for proteomic and enzymatic analysis of serum proteins.
    Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 02/2011; 879(5-6):386-94. · 2.78 Impact Factor

Full-text (2 Sources)

View
102 Downloads
Available from
Jun 4, 2014