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Battle KN, Uba FI, Soper SA. Microfluidics for the analysis of membrane proteins: How do we get there? Electrophoresis 2014; 35:2253-66. [DOI: 10.1002/elps.201300625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/16/2014] [Accepted: 02/17/2014] [Indexed: 01/22/2023]
Affiliation(s)
- Katrina N. Battle
- Department of Chemistry; Louisiana State University; Baton Rouge LA USA
| | - Franklin I. Uba
- Department of Chemistry; University of North Carolina; Chapel Hill NC USA
| | - Steven A. Soper
- Department of Chemistry; Louisiana State University; Baton Rouge LA USA
- Department of Chemistry; University of North Carolina; Chapel Hill NC USA
- Department of Biomedical Engineering; University of North Carolina; Chapel Hill NC USA
- BioFluidica, LLC, c/o Carolina Kick-Start; Chapel Hill NC USA
- School of Nano-Bioscience and Chemical Engineering; Ulsan National Institute of Science and Technology; Ulsan Korea
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2
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Effective Solubilization Procedure for Analysis of Silkworm Hemolymph Proteins by Two-Dimensional Gel Electrophoresis. Appl Biochem Biotechnol 2013; 169:1459-66. [DOI: 10.1007/s12010-012-0067-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/26/2012] [Indexed: 10/27/2022]
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3
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Reed PW, Densmore A, Bloch RJ. Optimization of large gel 2D electrophoresis for proteomic studies of skeletal muscle. Electrophoresis 2012; 33:1263-70. [PMID: 22589104 DOI: 10.1002/elps.201100642] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We describe improved methods for large format, two-dimensional gel electrophoresis (2DE) that improve protein solubility and recovery, minimize proteolysis, and reduce the loss of resolution due to contaminants and manipulations of the gels, and thus enhance quantitative analysis of protein spots. Key modifications are: (i) the use of 7 M urea and 2 M thiourea, instead of 9 M urea, in sample preparation and in the tops of the gel tubes; (ii) standardized deionization of all solutions containing urea with a mixed bed ion exchange resin and removal of urea from the electrode solutions; and (iii) use of a new gel tank and cooling device that eliminate the need to run two separating gels in the SDS dimension. These changes make 2DE analysis more reproducible and sensitive, with minimal artifacts. Application of this method to the soluble fraction of muscle tissues reliably resolves ~1800 protein spots in adult human skeletal muscle and over 2800 spots in myotubes.
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Affiliation(s)
- Patrick W Reed
- The Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, Department of Physiology, University of Maryland School of Medicine University of Maryland, Baltimore, MD 21201, USA.
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Righetti PG, Candiano G. Recent advances in electrophoretic techniques for the characterization of protein biomolecules: a poker of aces. J Chromatogr A 2011; 1218:8727-37. [PMID: 21536293 DOI: 10.1016/j.chroma.2011.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 04/02/2011] [Accepted: 04/04/2011] [Indexed: 12/15/2022]
Abstract
The four classical modes of electrophoresis of protein molecules (sodium dodecyl sulphate electrophoresis, SDS-PAGE, isoelectric focusing, IEF, and immobilized pH gradients, IPGs, two-dimensional maps, 2D, and capillary electrophoresis, CE) are here reviewed, with special emphasis on recent innovations. Thus, in the case of SDS-PAGE, a novel method, consisting in focusing SDS-protein micelles against a gradient of cationic charges grafted onto a polyacrylamide gel is presented. In the case of IEF, the recent decoding of the structure, polydispersity, molecular mass distribution and buffering properties of the soluble carrier ampholyte buffers are here discussed. In regard to two dimensional mapping, recent instrumentation for performing 2D maps in horizontal, large gel slabs (up to 30 cm × 40 cm) and in a radial format for the SDS dimension is here evaluated. Finally, in the case of CE, three major applications are presented: a thorough study of capillary IEF and of all experimental variables, a method of importance in screening of rDNA products; the possibility of running proteins and peptide separations in very acidic, amphoteric, isoelectric buffers in absence of any capillary coating; finally, the possibility of producing a facile, user friendly, covalent coating of the wall silanols via bonding of quaternarized piperazines endowed with an iodinated tail. In acidic, volatile buffers, such protein/peptide runs can be directly interfaced with mass spectrometry instrumentation.
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Affiliation(s)
- Pier Giorgio Righetti
- Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy.
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Lee H, Han J, Lee K, Kim E, Jin Y, Oh J, Hwang J, Kang H, Kim S, Seo K, Kang S, Choi Y. Buffer optimization for bovine Longissimus muscle tissues: Proteome analysis of Korean native cattle using 2-dimensional gel electrophoresis. Food Sci Biotechnol 2010. [DOI: 10.1007/s10068-010-0157-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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6
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Lee JS, Park HJ, Kim YH, Lee GM. Protein reference mapping of dihydrofolate reductase-deficient CHO DG44 cell lines using 2-dimensional electrophoresis. Proteomics 2010; 10:2292-302. [DOI: 10.1002/pmic.200900430] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Two-dimensional electrophoresis: an overview. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2009; 519:1-16. [PMID: 19381573 DOI: 10.1007/978-1-59745-281-6_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Two-dimensional gel electrophoresis (2DE) separates proteins by molecular charge and molecular size. Proteins are first solubilised in a denaturing buffer containing a neutral chaotrope, a zwitterionic or neutral detergent, and a reducing agent. First-dimension isoelectric keywords, focusing, then subjects proteins to a high voltage within a pH gradient. The amphoteric nature of proteins means each migrates to the pH where the net molecular charge is zero. After equilibration, to ensure complete protein unfolding, the second dimension separates by molecular size. Each protein is therefore resolved at a unique isoelectric point/molecular size coordinate. After visualisation by staining proteome changes are revealed by gel image analysis, and protein spots of interest excised and identified by mass spectrometry sequence analysis combined with database comparison. Variations to this procedure include staining or radio-labelling prior to electrophoresis. Although 2DE does have limitations, the most significant being the resolution of membrane and/or hydrophobic proteins, the potential solutions offered by pre-fractionation or adjustments to the electrophoresis regimen mean this technique is likely to remain central to proteomic research.
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9
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Ruan Y, Wan M. An optimized procedure for solubilization, reduction, and transfer of human breast cancer membrane-enriched fraction by 2-DE. Electrophoresis 2007; 28:3333-40. [PMID: 17722185 DOI: 10.1002/elps.200700035] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The separation of integral and peripheral membrane proteins is still a challenge, although many achievements have been made in the 2-DE-based membrane proteomics. Using a human breast cancer cell line, MCF-7, we investigated the influences of Tris, reducing reagents, cup loading, and SDS on membrane protein solubilization and separation by 2-DE. The addition of Tris to the sample solution improved the solubilization of the membrane-enriched fraction, and the best-quality gel patterns were obtained at 20 mM Tris. Tributylphosphine (TBP), a reducing agent, was not optimum in the 2-DE process because it not only decreased the solubilization of hydrophobic proteins but also caused some proteins, such as hsp60, prohibitin, and actin, to be resolved to a string of spots. However, when combined with DTT, TBP could improve the resolution of 2-DE patterns. Cup loading significantly facilitated the entrance of membrane proteins into IPG strips and over 1000 protein spots with high resolution were visualized. Adopting this strategy, an ATP synthase alpha chain was resolved into two adjacent spots for the first time in 2-DE gel patterns through the adding DTT in the middle of the IEF. A high SDS concentration in the equilibration buffer enhanced the transfer and increased the staining intensity of 50% of the protein spots in the gels, but also resulted in losses of some spots.
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Affiliation(s)
- Yusong Ruan
- The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi' an, PR China
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Iiizumi G, Sadoya Y, Hino S, Shibuya N, Kawabata H. Proteomic characterization of the site-dependent functional difference in the rat small intestine. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:1289-98. [PMID: 17881305 DOI: 10.1016/j.bbapap.2007.07.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 07/11/2007] [Accepted: 07/20/2007] [Indexed: 11/25/2022]
Abstract
To investigate the site-dependent functional difference in the small intestine, proteomic analysis was carried out on the three distinct parts of the rat small intestine. Male Wistar rats (7 weeks old) were fed a semi-purified diet ad libitum for 1 week. Intestinal tissues from the proximal, middle and distal regions of the small intestine were subjected to two-dimensional polyacrylamide gel electrophoresis, and the abundance of each spot was determined fluorometrically. MALDI-TOF/MS and LC-MS/MS analysis of the tryptic peptides were performed to identify the proteins. Many of the 180 identified proteins showed a distinctive distribution pattern along the small intestine. Glutathione S-transferase, Catechol O-methyltransferase and Villin 2 decreased gradually from the jejunum to the ileum, in contrast, non-specific dipeptidase and Keratin 19 increased gradually toward the ileum. The voltage-dependent anion channel 2 was most abundant in the duodenum while the L- and I-Fatty acid binding protein (FABP) and Cellular retinol binding protein (CRBP-II) were in the jejunum, and the Bile acid binding protein (BABP) was only observed in the ileum. The findings of these and of another proteins identified in this study may contribute to further understanding of the small intestinal function, and to clinical applications of small intestinal diseases.
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Affiliation(s)
- Gotaro Iiizumi
- Laboratory for Nutritional Biochemistry, School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
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11
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The study of three extraction methods for pre-separation and enrichment: Application to the complex proteome separation in rat liver. Sep Purif Technol 2006. [DOI: 10.1016/j.seppur.2006.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Vâlcu CM, Schlink K. Efficient extraction of proteins from woody plant samples for two-dimensional electrophoresis. Proteomics 2006; 6:4166-75. [PMID: 16791823 DOI: 10.1002/pmic.200500660] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein extraction from plant samples is usually challenging due to the low protein content and high level of contaminants. Therefore, the 2-DE pattern resolution is strongly influenced by the procedure of sample preparation. Efficient solubilization of proteins strictly depends on the chaotrope and detergent in the extraction buffer. Despite the large number of detergents that have been developed for the use in protein extraction and IEF, there is no single compound able to efficiently extract proteins from any source. Hence, optimization has to be performed for each type of sample. We tested several chaotrope/detergent combinations to achieve optimal solubilization and separation of proteins from Norway spruce [Picea abies (L.) H. Karst.] needles and European beech (Fagus sylvatica L.) leaves and roots. The same chaotrope mixture (7 M urea, 2 M thiourea) was found to be suitable for the extraction and separation of proteins from all samples. Nonetheless, the efficiency of the surfactants tested varied between samples so that optimal extraction and separation was achieved with different detergents or combination of detergents for each sample. The 2-DE separation of spruce needle proteins was optimal in a mixture of two zwitterionic detergents (2% CHAPS and 2% decyl dimethylammonio propanesulfonate). Beech proteins were best separated in buffers containing sugar-based detergents (2% n-octyl beta-D-glucopiranoside in the case of leaf samples and 2% dodecyl maltoside for the root samples). IEF was performed in buffers with the same composition as the extraction buffer except for the root proteins that were better focused in a buffer containing 2% CHAPS.
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Affiliation(s)
- Cristina-Maria Vâlcu
- Section of Forest Genetics, Technische Universität München, Freising-Weihenstephan, Germany.
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Ren D, Julka S, Inerowicz HD, Regnier FE. Enrichment of cysteine-containing peptides from tryptic digests using a quaternary amine tag. Anal Chem 2006; 76:4522-30. [PMID: 15283597 DOI: 10.1021/ac0354645] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new strategy for specifically targeting cysteine-containing peptides in a tryptic digest is described. The method is based on quantitatively derivatizing cysteine residues with a quaternary amine tag (QAT). Tags were introduced into proteins following reduction of disulfide bonds through derivatization of cysteine residues with (3-acrylamidopropyl)trimethylammonium chloride. After trypsin digestion, derivatized cysteine-containing peptides were enriched by strong cation exchange chromatography. The method was validated using model peptides and a protein. The QAT strategy has several advantages over other methods for the selection of cysteine-containing peptides. One is that it increases the ionization efficiency of cysteine-containing peptides. The other is that chromatographic selection is achieved with simple, robust cation exchange chromatography columns. As a result, this new strategy provides a simple way to facilitate enrichment of cysteine-containing peptides, thereby reducing sample complexity in bottom-up proteomics.
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Affiliation(s)
- Diya Ren
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
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de Marqui ABT, Vidotto A, Polachini GM, Bellato CDM, Cabral H, Leopoldino AM, de Góis Filho JF, Fukuyama EE, Settanni FAP, Cury PM, Bonilla-Rodriguez GO, Palma MS, Tajara EH. Solubilization of Proteins from Human Lymph Node Tissue and Two-Dimensional Gel Storage. BMB Rep 2006; 39:216-22. [PMID: 16584638 DOI: 10.5483/bmbrep.2006.39.2.216] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present study, we compared six different solubilization buffers and optimized two-dimensional electrophoresis (2-DE) conditions for human lymph node proteins. In addition, we developed a simple protocol for 2-D gel storage. Efficient solubilization was obtained with lysis buffers containing (a) 8 M urea, 4% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), 40 mM Tris base, 65 mM DTT (dithiothreitol) and 0.2% carrier ampholytes; (b) 5 M urea, 2 M thiourea, 2% CHAPS, 2% SB 3-10 (N-decyl-N,N-dimethyl-3-ammonio-1-propanesulfonate), 40 mM Tris base, 65 mM DTT and 0.2% carrier ampholytes or (c) 7 M urea, 2 M thiourea, 4% CHAPS, 65 mM DTT and 0.2% carrier ampholytes. The optimal protocol for isoelectric focusing (IEF) was accumulated voltage of 16,500 Vh and 0.6% DTT in the rehydration solution. In the experiments conducted for the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), best results were obtained with a doubled concentration (50 mM Tris, 384 mM glycine, 0.2% SDS) of the SDS electrophoresis buffer in the cathodic reservoir as compared to the concentration in the anodic reservoir (25 mM Tris, 192 mM glycine, 0.1% SDS). Among the five protocols tested for gel storing, success was attained when the gels were stored in plastic bags with 50% glycerol. This is the first report describing the successful solubilization and 2D-electrophoresis of proteins from human lymph node tissue and a 2-D gel storage protocol for easy gel handling before mass spectrometry (MS) analysis.
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Zhang JS, Liu F, Conwell CC, Tan Y, Huang L. Mechanistic studies of sequential injection of cationic liposome and plasmid DNA. Mol Ther 2006; 13:429-37. [PMID: 16242997 DOI: 10.1016/j.ymthe.2005.08.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Revised: 08/19/2005] [Accepted: 08/19/2005] [Indexed: 11/26/2022] Open
Abstract
We previously reported that sequential injection of cationic liposome and plasmid DNA leads to notably reduced inflammatory toxicity and improved transfection in the lung (Y. Tan et al., 2001, Mol. Ther. 3, 673-682). The purpose of the current study was to explore the mechanism involved in sequential injection. It was observed that sequential injection resulted in dramatically lower DNA uptake by the liver and higher DNA levels in the lung than the lipoplex injection. In vitro experiments with macrophage cells further showed that sequential addition of liposomes and DNA could diminish the cellular uptake of DNA by these cells. The contributions of serum to the enhanced bioactivity and decreased toxicity were examined by injecting mice with samples of premixed liposome with serum and then DNA (LSD sample), and the resulting activities were compared to those obtained with injection of lipoplex-serum mixtures (LDS sample). LSD yielded 80% lower TNF-alpha levels and over 10-fold higher transfection than lipoplex, which is consistent with the reported findings with sequential injection. In contrast, LDS resulted in the same TNF-alpha levels and comparable transfection with lipoplex. Thus, the results suggest that the primary interaction of serum with liposome is a critical factor contributing to the superior activity and reduced toxicity of sequential injection. Studies on the interaction between mouse serum, liposomes, and DNA showed that DNA could bind negatively charged liposome-serum complex to form a ternary complex, which has a density similar to that of the ternary complex formed between lipoplex with serum. Further in vitro tests showed that LSD and LDS were similar in particle size and protein content, but different in protein composition as observed by 2-D gel electrophoresis. In addition, DNA in LSD was more readily displaced by dextran sulfate, an anionic polymer, than in LDS. The above findings suggest that the inhibition of opsonin protein binding on the particle surface with the sequential injection may contribute to the reduced macrophage uptake and cytokine induction and that the high ability of DNA release from the particles formed after sequential injection may contribute to the improved lung gene transfection.
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Affiliation(s)
- Jing-Shi Zhang
- Center for Pharmacogenetics, School of Pharmacy, University of Pittsburgh, PA 15213, USA
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Abstract
Many proteins with extreme physical properties, including basic and acidic proteins, membrane proteins, and very large proteins, present specific challenges to 2-DE separation. Using a pressure-blotting approach, we demonstrate that a basic integral membrane protein, mitochondrial ATP-binding cassette protein 1 (mABC1), focuses in the IPG strip, but fails to enter into the 2-D SDS-PAGE gel. Through modifying the equilibration conditions between the IPG strip and 2nd dimension, we demonstrate that only by increasing both the volume (from 3 to 6 mL for a 7-cm strip) and SDS concentration (from 2 to 10%) of the equilibration buffer is migration of mABC1 into the 2nd dimension achieved. While 2-DE remains one of the core separation technologies of proteomic analysis, proteins that are extremely basic, hydrophobic, or of large mass present significant challenges to 2-DE separation due to aggregation, oxidation, precipitation, and the physical limitations of the 1-D IPG strip. Since the advent of commercially available IPG strips, numerous groups have experimented with IEF conditions using various detergents alone or in combination, alternative denaturants, and thiol oxidation agents to improve protein focusing. Effective 2-DE separation of membrane proteins has been affected dramatically by these advances in protein solubilization, as well as improvements in isolation of membranes, delipidation, and active in-gel rehydration. Since the development of commercially available basic IPG strips, the most significant advance in the separation of basic proteins has been the introduction of hydroxyethyldisulfides, either alone or in combination with DTT. While hydrophobic proteins were once virtually absent from the 2-D gel, and basic proteins were only visible as dense streaks, now many groups are undertaking large-scale analyses of membranes and basic proteins. Using this base of experimental tools, we embarked on a proteomic analysis of cardiac mitochondrial membranes, hoping to combine the knowledge gained from ongoing targeted protein chemistry and molecular biology studies with a broader-based proteomic analysis. Of particular interest is the inner mitochondrial membrane protein mABC1 (mitochondrial ATP-binding cassette protein 1), which may play a significant role in cardioprotection as part of the mitochondrial ATP-sensitive potassium channels. Therefore, in designing our 2-DE approach, it was crucial to ensure that mABC1 is focused, observable, and quantifiable, despite being an integral membrane protein of pI 9.37.
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Affiliation(s)
- Jason McDonough
- Division of Cardiology, NHLBI Proteomics Center, Johns Hopkins University, Baltimore, MD 21205, USA
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Chapter 15 Electrophoresis of proteins and peptides. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s0301-4770(04)80028-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Hamdan M, Righetti PG. Assessment of protein expression by means of 2-D gel electrophoresis with and without mass spectrometry. MASS SPECTROMETRY REVIEWS 2003; 22:272-284. [PMID: 12884390 DOI: 10.1002/mas.10056] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Careful examination of current literature, particularly over the last 5 years, reveals a wide range of approaches for the relative quantification of protein expression in cells, tissues, and body fluids. In view of such an observation, it is reasonable to ask whether researchers need new methods, or whether it is more productive to optimize and tune already existing ones. It is generally agreed that none of the existing methodologies on its own can give a full account of protein expression in a complex medium; this limitation, however, has not prevented the use of existing methods to provide valuable information on a wide range of proteins, where their expression has been correlated to certain pathologies and/or to pharmacological, genetic, or environmental factors. In the present work, an attempt is made to review the application of one of these methodologies, namely two-dimensional polyacrylamide gel electrophoresis on its own or in conjunction with mass spectrometry, to assess protein expression, particularly when such expression can be correlated to certain pathologies.
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Affiliation(s)
- Mahmoud Hamdan
- Computational, Analytical & Structural Sciences, GlaxoSmithKline, Verona, Italy.
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Bertelli R, Ginevri F, Caridi G, Dagnino M, Sandrini S, Di Duca M, Emma F, Sanna-Cherchi S, Scolari F, Neri TM, Murer L, Massella L, Basile G, Rizzoni G, Perfumo F, Ghiggeri GM. Recurrence of focal segmental glomerulosclerosis after renal transplantation in patients with mutations of podocin. Am J Kidney Dis 2003; 41:1314-21. [PMID: 12776285 DOI: 10.1016/s0272-6386(03)00364-0] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Posttransplant recurrence of focal segmental glomerulosclerosis (FSGS) occurs in a relevant proportion of FSGS patients and represents an important clinical emergency. It is taken as a proof of the existence of circulating permeability plasma factor(s) that are also putative effectors of original proteinuria in these patients. Familial forms of FSGS do not recur, but the discovery of numerous patients with sporadic FSGS and mutations of podocin (NPHS2, that is actually an inherited disease) who received a renal graft require a re-evaluation of the problem. METHODS To evaluate the incidence of posttransplant recurrence of FSGS in patients with NPHS2, the authors screened for podocin mutations in 53 patients with the clinical and pathologic stigmata of FSGS who had renal failure and who had undergone renal transplantation.Results. Twelve children were found to carry a homozygous (n9) or a heterozygous (n4) mutation of podocin and were classified, according to current criteria, as patients with inherited FSGS. In 5 patients of this group (38%), proteinuria recurred after renal graft and in 2, renal biopsy results showed recurrence of FSGS. Prerecurrence serum of 3 patients of this cohort was tested for antipodocin antibodies with indirect immuno-Western utilizing human podocyte extracts and were found negative. The rate of FSGS recurrence was comparable in non-NPHS2-FSGS children (12 of 27) and adults (3 of 13). Also clinical outcome of recurrence and response to plasmapheresis and immunosuppressors were comparable, suggesting a common mechanism. CONCLUSION These data show a high rate of FSGS recurrence in patients with NPHS2 mutations that is comparable with idiopathic FSGS and describe the successful therapeutic approach. Recurrence of an apparently inherited disease should stimulate a critical review of the mechanisms of recurrence and of original proteinuria in these cases.
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Affiliation(s)
- Roberta Bertelli
- Laboratory on Pathophysiology of Uremia, G. Gaslini Children's Hospital,Genoa, Italy
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Righetti PG, Castagna A, Antonucci F, Piubelli C, Cecconi D, Campostrini N, Zanusso G, Monaco S. The proteome: anno Domini 2002. Clin Chem Lab Med 2003; 41:425-38. [PMID: 12747583 DOI: 10.1515/cclm.2003.065] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We present some current definitions related to functional and structural proteomics and the human proteome, and we review the following aspects of proteome analysis: Classical 2-D map analysis (isoelectric focusing (IEF) followed by SDS-PAGE); Quantitative proteomics (isotope-coded affinity tag (ICAT), fluorescent stains) and their use in e.g., tumor analysis and identification of new target proteins for drug development; Electrophoretic pre-fractionation (how to see the hidden proteome!); Multidimensional separations, such as: (a) coupled size-exclusion and reverse-phase (RP)-HPLC; (b) coupled ion-exchange and RP-HPLC; (c) coupled RP-HPLC and RP-HPLC at 25/60 degrees C; (d) coupled RP-HPLC and capillary electrophoresis (CE); (e) metal affinity chromatography coupled with CE; Protein chips. Some general conclusions are drawn on proteome analysis and we end this review by trying to decode the glass ball of the aruspex and answer the question: "Quo vadis, proteome"?
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Affiliation(s)
- Pier Giorgio Righetti
- Department of Agricultural and Industrial Biotechnologies, Faculty of Sciences, University of Verona, Verona, Italy.
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Ghiggeri GM, Bruschi M, Candiano G, Rastaldi MP, Scolari F, Passerini P, Musante L, Pertica N, Caridi G, Ferrario F, Perfumo F, Ponticelli C. Depletion of clusterin in renal diseases causing nephrotic syndrome. Kidney Int 2002; 62:2184-94. [PMID: 12427144 DOI: 10.1046/j.1523-1755.2002.00664.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Clusterin is a lipoprotein that has anti-complement effects in membranous nephropathy (MN). In focal segmental glomerulosclerosis (FSGS), it inhibits permeability plasma factor activity and could influence proteinuria. Moreover, with aging, knockout mice for clusterin develop a progressive glomerulopathy with sclerosis. METHODS Since little is known about clusterin metabolism in humans, we determined clusterin levels and composition in the sera and urine of 23 patients with MN, 25 with FSGS and 23 with steroid-responsive nephrotic syndrome (NS). Renal localization was evaluated by immunofluorescence and morphometry. RESULTS Serum clusterin was markedly reduced in active MN, in FSGS and in children with NS compared to controls; after stable remission of proteinuria, nearly normal levels were restored. Among various biochemical variables, serum clusterin was inversely correlated with hypercholesterolemia. Urinary clusterin, representing a 0.01 fraction of serum, was higher in the urine from normal subjects and FSGS patients in remission with proteinuric MN, FSGS and idiopathic NS; clusterin was inversely correlated with proteinuria. In all cases, urinary and serum clusterin was composed of the same 80 kD isoforms. Finally, a decrease in focal segmental or global clusterin staining was found in FSGS glomeruli, especially in areas of sclerosis. Instead, in MN an overall increment of staining was observed that ranged from mild/focal to very intense/diffuse. CONCLUSIONS The overall pool of clusterin is reduced in glomerular diseases causing nephrotic syndrome, with hypercholesterolemia appearing as the unifying feature. Depletion of clusterin should negatively affect the clinical outcome in nephrotic patients and efforts should be aimed at normalizing clusterin overall pool.
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Affiliation(s)
- Gian Marco Ghiggeri
- Laboratory on Pathophysiology of Uremia and Unit of Nephrology, Istituto Giannina Gaslini, Genova, Italy.
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22
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Oh-Ishi M, Maeda T. Separation techniques for high-molecular-mass proteins. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 771:49-66. [PMID: 12015992 DOI: 10.1016/s1570-0232(02)00112-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many high-molecular-mass (HMM) proteins (MW>100 kDa) are known to be involved in cytoskeleton, defence and immunity, transcription and translation in higher eukaryotic organisms. Even in the post-genomic era, purification of HMM protein is the first important step to analyze protein composition in a tissue or a cell (proteomics), to determine protein tertiary structure (structural biology), and to investigate protein function (functional genomics). To separate a HMM protein from a protein mixture, ions, chaotropes (urea and thiourea), detergents and protease inhibitors in extraction media and buffer solutions either for liquid chromatography or for gel electrophoresis should be carefully chosen, since HMM proteins tend to be aggregates under denatured condition and their long polypeptide chains are easily attacked by intrinsic proteases during separation procedure. Among many liquid chromatography techniques, affinity chromatography either with sequence-specific DNA for transcription factor, or with monoclonal antibody specific for myosin heavy chain has been used for preparative isolation of the respective HMM proteins. Though SDS-PAGE could analyze the size and the quantity of megadalton proteins, the resolution of HMM proteins is relatively poor. A newly developed pulse SDS-PAGE would be able to raise the resolution of HMM proteins compared with the conventional SDS-PAGE. The 2-DE method is not particularly suitable in analyzing HMM proteins larger than 200 kDa. However, a 2-DE method that uses an agarose IEF gel in the first dimension (agarose 2-DE) has been shown to produce significant improvements in 2-DE separation of HMM proteins larger than 150 kDa and up to 500 kDa.
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Affiliation(s)
- Masamichi Oh-Ishi
- Laboratory of Biomolecular Dynamics, Department of Physics, Kitasato University School of Science, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
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23
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Musante L, Candiano G, Bruschi M, Zennaro C, Carraro M, Artero M, Giuffrida MG, Conti A, Santucci A, Ghiggeri GM. Characterization of plasma factors that alter the permeability to albumin within isolated glomeruli. Proteomics 2002; 2:197-205. [PMID: 11840565 DOI: 10.1002/1615-9861(200202)2:2<197::aid-prot197>3.0.co;2-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Focal segmental glomerulosclerosis (FSGS) is responsible for intractable proteinuria and has become the leading cause of renal insufficiency in children. Protenuria in FSGS is probably due to the effect of one or more permeability plasma factors which increase the glomerular permeability to proteins. We fractioned serum from children with FSGS using two mixed chromatographic-electrophoretic approaches and have purified ten proteins among several hundreds which maintained the original permeability activity after renaturation, utilizing an isolated rat glomeruli assay. Six proteins were successfully characterized by mass spectometry as fibulin, apolipoprotein J, vitronectin, albumin isoforms, gamma chain fibrinogen and mannan-binding lectin-associated serine protease. Both procedures utilized for purification were based on affinity chromatography with Protein A-Sepharose and ended with two-dimensional electrophoresis, whereas the intermediate steps were different. Cross inhibition with zinc and aprotinin of purified factors and whole FSGS serum indicate strong homology. These are the first data demonstrating permeability activity for serum proteins, an observation with important implications in pathogenesis of proteinuria. Determination of the serum levels of each protein and a careful differentiation of FSGS from normal serum could provide the basis for clarifying the mechanism of proteinuria.
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Affiliation(s)
- Luca Musante
- Laboratorio di Fisiopatologia dell'uremia, Istituto G. Gaslini, Genova, Italy
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24
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Righetti PG, Verzola B. Folding/unfolding/refolding of proteins: present methodologies in comparison with capillary zone electrophoresis. Electrophoresis 2001; 22:2359-74. [PMID: 11519938 DOI: 10.1002/1522-2683(200107)22:12<2359::aid-elps2359>3.0.co;2-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A series of techniques for monitoring protein folding/unfolding/misfolding equilibria are here assessed and compared with capillary zone electrophoresis (CZE). They include spectroscopic techniques, such as circular dichroism, intrinsic fluorescence, nuclear magnetic resonance, Fourier transform infrared and Raman spectroscopy, small-angle X-ray scattering, as well as techniques based on biological assays, such as limited proteolysis and immunochemical analysis of different conformational states. Some unusual probes, such as mass spectrometry for probing unfolding transitions, are also discussed. Size-exclusion chromatography is also evaluated in view of the fact that this technique, like all electrophoretic techniques, and unlike spectroscopic probes, which can only see an average signal in mixed populations, can indeed physically separate folded vs. unfolded macromolecules, especially in the case of slow equilibria. Particular emphasis is devoted to electrophoretic techniques, such as gel-slab electrophoresis in transverse urea or thermal gradients, and CZE. In the latter case, a number of applications are shown, demonstrating the excellent correlation of CZE with more traditional probes, such as intrinsic fluorescence monitoring. It is additionally shown that CZE can be used for measuring the deltaG degrees of unfolding over the pH scale, in good agreement with theoretical calculations on the electrostatic free energy of folding vs. pH, as calculated with a linearized Poisson-Boltzmann equation. Finally, it is demonstrated that CZE can probe also aggregate formation in the presence of helix-inducing agents, such as trifluorethanol.
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Affiliation(s)
- P G Righetti
- University of Verona, Department of Agricultural and Industrial Biotechnologies, Italy.
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25
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Galvani M, Rovatti L, Hamdan M, Herbert B, Righetti PG. Protein alkylation in the presence/absence of thiourea in proteome analysis: a matrix assisted laser desorption/ionization-time of flight-mass spectrometry investigation. Electrophoresis 2001; 22:2066-74. [PMID: 11465507 DOI: 10.1002/1522-2683(200106)22:10<2066::aid-elps2066>3.0.co;2-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Although it is highly recommended that reduction and alkylation of free -SH groups in proteins should be performed prior to any electrophoretic step (including the first isoelectric focusing/immobilized pH gradient (IEF/IPG) dimension), it is here reported that one component of the sample solubilization cocktail adopted recently (namely thiourea) strongly quenches such alkylation process (as typically carried out with iodoacetamide, IAA). The present matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis demonstrates that thiourea is an effective scavenger of IAA, since its sulfur atom reacts as efficiently as the ionized, free -SH group of Cys in proteins at alkaline pH values (pH 8.5-9.0). As a result of this reaction, free IAA is quickly depleted by thiourea, via the formation of an intermediate adduct, which is rapidly deamidated to form the cyclic compound thiazolinidone monoimine. This reaction strongly competes with the direct addition reaction of IAA onto the -SH group in proteins, resulting in poorly alkylated proteins. It is, therefore, recommended that, whenever possible and compatible with the type of sample, thiourea should be omitted from the solubilizing cocktail in proteome analysis. However, after proper sample reduction and alkylation, thiourea can be incorporated into the IEF/IPG gel, where it will have the beneficial effect of augmenting protein solubility at their pI values and scavenging the excess of free IAA.
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Affiliation(s)
- M Galvani
- GlaxoWellcome SpA, Medicines Research Center, Verona, Italy
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26
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Candiano G, Musante L, Zennaro C, Bruschi M, Carraro M, Artero M, Gusmano R, Ginevri F, Perfumo F, Ghiggeri G. Inhibition of renal permeability towards albumin: a new function of apolipoproteins with possible pathogenetic relevance in focal glomerulosclerosis. Electrophoresis 2001; 22:1819-25. [PMID: 11425237 DOI: 10.1002/1522-2683(200105)22:9<1819::aid-elps1819>3.0.co;2-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a degenerative renal disease characterized by the accumulation of extracellular matrix and lipids within the glomerular tuft. It has been proposed that an abnormal renal permeabilization towards proteins induced by a putative plasma factor is, in some way, involved in the pathogenesis of the disease. In this paper, we measured the plasma permeability activity (Palb) in several sera of patients with FSGS and found a mean activity of 0.82+/-0.03 which means a marked increase compared to a mean Palb of 0.16+/-0.03 in normal controls. Coincubation of FSGS and normal serum reduced the permeability activity within the normal range; normal serum added to the incubation medium after the glomeruli had already been exposed to the FSGS serum had no effect, suggesting the presence of inhibitory substances with a direct effect on a circulating substrate. Finally, the antipermeability activity was retained when heated to 60 degrees C but not to 100 degrees C. By serial fractionations of normal serum and reported activity measurements at each step, five natural occurring inhibitors of albumin permeabilization were purified and characterized by matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS), as components of apolipoproteins (apo) (apo E2 and E4, apo L, the high Mr apo J and a 28 kDa fragment of apo A-IV). Coincubation of each apolipoprotein with FSGS serum inhibited permeability, but only apo J and apo E2 and E4 were found to be crucial for the process. In conclusion, we have purified from normal serum five inhibitors of permeability induced by FSGS serum, all corresponding to apolipoproteins. An imbalance between permeability factors and apolipoproteins may play a pathogenetic role in FSGS.
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Affiliation(s)
- G Candiano
- Unit and Laboratory of Nephrology, G. Gaslini Children Hospital, Genova, Italy
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27
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Candiano G, Musante L, Carraro M, Faccini L, Campanacci L, Zennaro C, Artero M, Ginevri F, Perfumo F, Gusmano R, Ghiggeri GM. Apolipoproteins prevent glomerular albumin permeability induced in vitro by serum from patients with focal segmental glomerulosclerosis. J Am Soc Nephrol 2001; 12:143-150. [PMID: 11134260 DOI: 10.1681/asn.v121143] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Glomerular albumin permeability alterations can be induced in vitro by serum from patients with end-stage renal disease caused by primary focal segmental glomerulosclerosis (FSGS). It was hypothesized that inhibitory substances may be present in normal serum, which may prevent the permeability alterations in isolated glomeruli, and the present study sought to isolate and characterize these factors. Albumin permeability was determined from the change in glomerular volume induced by applying oncotic gradients across the basement membrane of healthy isolated rat glomeruli preincubated with FSGS serum and normal serum fractionated using standard techniques. Fractions of normal serum with inhibitory activity obtained by a multistep chromatographic procedure underwent two-dimensional electrophoresis and staining. Approximately 50 protein spots were recovered, renatured, and tested for antipermeability activity. Five of these proteins demonstrated consistent inhibitory activity, and desorption ionization and mass spectrometry proved them to be components of high-density lipoprotein: apolipoproteins (apo) E(2) and E(4), high-molecular-weight J and L, and a 28-kD fragment of A-IV. Polyclonal antibodies to apo E or apo J added to the whole normal serum restored the permeability activity of the FSGS serum in the bioassay. Commercially available apo E and apo J also demonstrated antipermeability activity when added to FSGS serum. Cyanogen bromide digestion of apo A-IV produced fragments that inhibited the permeability activity of the FSGS serum, whereas the intact protein did not. Thus, components of high-density lipoprotein are capable of preventing glomerular albumin permeability induced by serum from patients with FSGS in an in vitro system. The specificity and mechanism of the inhibition remain to be determined; the alteration of normal inhibitory activity in vivo may be a component in the pathophysiology of FSGS.
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Affiliation(s)
- Giovanni Candiano
- Unit and Laboratory of Nephrology, Istituto G. Gaslini, Genoa, Italy
| | - Luca Musante
- Unit and Laboratory of Nephrology, Istituto G. Gaslini, Genoa, Italy
| | - Michele Carraro
- Istituto di Medicina Clinica, University of Trieste, Trieste, Italy
| | - Luigi Faccini
- Istituto di Medicina Clinica, University of Trieste, Trieste, Italy
| | | | - Cristina Zennaro
- Istituto di Medicina Clinica, University of Trieste, Trieste, Italy
| | - Mary Artero
- Istituto di Medicina Clinica, University of Trieste, Trieste, Italy
| | - Fabrizio Ginevri
- Unit and Laboratory of Nephrology, Istituto G. Gaslini, Genoa, Italy
| | - Francesco Perfumo
- Unit and Laboratory of Nephrology, Istituto G. Gaslini, Genoa, Italy
| | - Rosanna Gusmano
- Unit and Laboratory of Nephrology, Istituto G. Gaslini, Genoa, Italy
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Chapter 14 Two-dimensional maps. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0301-4770(01)80046-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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29
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Abstract
Two-dimensional electrophoresis (2-DE) is a highly resolving technique for arraying proteins by isoelectric point and molecular mass. To date, the resolving ability of 2-DE for protein separation is unsurpassed, thus ensuring its use as the fundamental separation method for proteomics. When immobilized pH gradients (IPGs) are used for isoelectric focusing in the first dimension, excellent reproducibility and high protein load capacity can be achieved. While this has been beneficial for separations of soluble and mildly hydrophobic proteins, separations of membrane proteins and other hydrophobic proteins with IPGs have often been poor. Stimulated by the growing interest in proteomics, recent developments in 2-DE methodology have been aimed at rectifying this situation. Improvements have been made in the area of protein solubilization and sample fractionation, leading to a revamp of traditional approaches for 2-DE of membrane proteins. This review explores these developments.
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Affiliation(s)
- M P Molloy
- Australian Proteome Analysis Facility, Macquarie University, Sydney.
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Pock K, Rizzi A, Josic D. Use of high-resolution techniques for the characterization of clotting factor VIII. J Chromatogr A 1999; 852:175-88. [PMID: 10480242 DOI: 10.1016/s0021-9673(99)00620-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Dealing with the structural characterization of clotting factor VIII (FVIII) requires the application of several high-resolution analytical techniques. Besides the analytical point of view, a detailed knowledge of FVIII structure, production and therapeutic application is necessary. This review gives an overview of most of the currently applied analytical methods and how they deal with the complex analytical problem, investigating FVIII in a sample matrix containing large amounts of accompanying plasma proteins.
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Affiliation(s)
- K Pock
- Octapharma Pharmazeutika Produktionsges.m.b.H., Vienna, Austria.
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31
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Musante L, Ulivi M, Cutrona G, Chiorazzi N, Roncella S, Candiano G, Ferrarini M. Identification of HSP-60 as the specific antigen of IgM produced by BRG-lymphoma cells. Electrophoresis 1999; 20:1092-7. [PMID: 10344290 DOI: 10.1002/(sici)1522-2683(19990101)20:4/5<1092::aid-elps1092>3.0.co;2-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In previous studies we described a patient with Burkitt's lymphoma and AIDS, whose cells recognized a molecule expressed by normal and malignant breast cells. In the present study, we identified this antigen by two-dimensional (2-D) electrophoresis and Western blotting using the antibody produced by lymphoma cells. The antigen so identified consisted of two clusters of spots with a molecular mass (Mr) of 60 and 50 kDa, respectively. Preparative immobilized pH gradient (IPG) was subsequently used to isolate the clusters of spots of higher molecular masses, from which peptide fragments of approximately 10 aa were separated on reverse-phase chromatography and sequenced. This procedure enabled the identification of the antigen recognized by the lymphoma cells as HSP-60. By means of serological analyses it was possible to identify the lower molecular mass cluster of spots as a molecule related to HSP-60. It is hypothesized that this molecule is a membrane form of HSP-60 that differs from HSP-60 in a COOH terminal portion.
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Affiliation(s)
- L Musante
- Department of Nephrology, Giannina Gaslini Children Hospital, Genova, Italy.
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