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Determination of Peptide and Protein Disulfide Linkages by MALDI Mass Spectrometry. Top Curr Chem (Cham) 2012; 331:79-116. [DOI: 10.1007/128_2012_384] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Hachmann JP, Amshey JW. Models of protein modification in Tris-glycine and neutral pH Bis-Tris gels during electrophoresis: effect of gel pH. Anal Biochem 2005; 342:237-45. [PMID: 15935323 DOI: 10.1016/j.ab.2005.04.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 04/09/2005] [Accepted: 04/12/2005] [Indexed: 11/16/2022]
Abstract
The pH of conventional Tris-glycine SDS-PAGE gels during a run is determined to be 9.5, in contrast to Bis-Tris-Mes gels where the pH is 7.2. Concentrations of free acrylamide are determined to be less than 10mM in commercial gels of both types, and it is found that of the major components in these gels, only glycine and protein amine or sulfhydryl functions are likely to react with residual acrylamide during the time frame of typical separations. The addition of acrylamide to sulfhydryl groups on proteins is modeled using glutathione and cysteine at acrylamide concentrations found in the commercial gels. Rate constants are determined for these reactions as well as for reaction with glycine at the pH that proteins will encounter in these gel types. The half-life for glutathione sulfhydryl at 10mM acrylamide and pH 7.2 is more than 4h at room temperature. Rates are significantly lower in Bis-Tris-Mes gels than in Tris-glycine gels, reducing the risk of adventitious protein modification. Commercial Bis-Tris-Mes gels provide a sample reduction buffer at pH 8.5 versus the conventional pH 6.8 of Tris-glycine gels. It is shown that significantly less protein degradation occurs during sample preparation at the higher pH used with Bis-Tris gels.
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Sarnighausen E, Wurtz V, Heintz D, Van Dorsselaer A, Reski R. Mapping of the Physcomitrella patens proteome. PHYTOCHEMISTRY 2004; 65:1589-1607. [PMID: 15276455 DOI: 10.1016/j.phytochem.2004.04.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2004] [Revised: 04/02/2004] [Indexed: 05/24/2023]
Abstract
The moss Physcomitrella patens is unique among land plants due to the high rate of homologous recombination in its nuclear DNA. The feasibility of gene targeting makes Physcomitrella an unrivalled model organism in the field of plant functional genomics. To further extend the potentialities of this seed-less plant we aimed at exploring the P. patens proteome. Experimental conditions had to be adopted to meet the special requirements connected to the investigations of this moss. Here we describe the identification of 306 proteins from the protonema of Physcomitrella. Proteins were separated by two dimensional electrophoresis, excised form the gel and analysed by means of mass spectrometry. This reference map will lay the basis for further profound studies in the field of Physcomitrella proteomics.
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Affiliation(s)
- Eric Sarnighausen
- Plant Biotechnology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg, Germany.
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Alvarez EJ, Larsen BS, Coldren CD, Rice J. Effect of residual acrylamide monomer from two-dimensional gels on matrix-assisted laser desorption/ionization peptide mass mapping experiments. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2000; 14:974-978. [PMID: 10844734 DOI: 10.1002/(sici)1097-0231(20000615)14:11<974::aid-rcm974>3.0.co;2-h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Residual acrylamide can cause severe suppression of signal intensity during matrix-assisted laser desorption/ionization (MALDI) peptide mass mapping experiments. This suppression phenomenon can compromise the ability to detect low picomole and subpicomolar amounts of peptides extracted from two-dimensional gels. A rapid and simple method that exploits the use of pipette tips incorporating C18 packing materials for the enhancement of MALDI signal intensity is presented. The utility of the method is demonstrated with peptide solutions incorporating residual acrylamide and/or gel monomer components.
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Affiliation(s)
- E J Alvarez
- Corporate Research and Development Wilmington, Delaware 19880, USA
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Michalski WP, Shiell BJ. Strategies for analysis of electrophoretically separated proteins and peptides. Anal Chim Acta 1999. [DOI: 10.1016/s0003-2670(98)00486-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Yan JX, Kett WC, Herbert BR, Gooley AA, Packer NH, Williams KL. Identification and quantitation of cysteine in proteins separated by gel electrophoresis. J Chromatogr A 1998; 813:187-200. [PMID: 9697320 DOI: 10.1016/s0021-9673(98)00319-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A simple technique is introduced to identify and quantitate cysteine (Cys) after acid hydrolysis of protein. The technique involves using 9-fluorenylmethyl chloroformate (Fmoc)-based amino acid analysis that recovers all of the amino acids (asparagine and glutamine are recovered in their acidic forms) except tryptophan. Cys adducts with acrylamide and iodoacetamide have been observed in hydrolysates of gel-separated proteins. To enable quantitation of Cys by amino acid analysis, different conditions of reduction [dithiothreitol (DTT) and tributylphosphine] and alkylation [vinylpyridine, acrylamide and iodoacetamide] were compared. Optimal conditions for on-blot reduction (125 mM of DTT, pH 8.5, at 80 degrees C) and alkylation (0.25 M iodoacetamide, pH 8.5, at 37 degrees C) of proteins which have been separated by gel electrophoresis and blotted onto polyvinylidenedifluoride (PVDF) membrane were established to achieve complete recovery of alkylated Cys. Even with the optimal on-blot iodoacetamide alkylation, there may still be some acrylamide adducts present and these were able to be separated by HPLC along with the other 16 amino acids. The Cys content has been successfully determined by Fmoc-amino acid analysis of PVDF-blotted proteins separated by 1D or 2D gel electrophoresis. Lysine alkylation with iodoacetamide and acrylamide has also been characterised. Protein identification using amino acid composition including Cys has been introduced.
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Affiliation(s)
- J X Yan
- Macquarie University Centre for Analytical Biotechnology, School of Biological Sciences, Macquarie University, Sydney, NSW, Australia
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Righetti PG, Bossi A. Isoelectric focusing in immobilized pH gradients: an update. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 699:77-89. [PMID: 9392369 DOI: 10.1016/s0378-4347(96)00151-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The latest trends on isoelectric focusing (IEF) in immobilized pH gradients (IPG) are here reviewed. The major advances on IPG technologies have been made when interfacing this technique with sodium dodecyl sulfate-polyacrylamide gel electrophoresis to produce two-dimensional (2-D) maps. Previous 2-D maps were routinely performed using conventional IEF as a first dimension, which typically resulted in poor reproducibility of spot position. With IPGs, correlation between experimental and calculated protein pI values is as good as +0.01 to 0.02 pH units. A new software has also been released, permitting easy calculation and optimization of linear, concave and convex exponential gradients, even in very complex recipes utilizing all ten Immobiline chemicals. It has also been proven that IPGs can be interfaced with mass spectrometry, thus obtaining a novel 2-D map with the best of pI measurements in the first dimension coupled with the best of mass determination in the second dimension. Recently, it has been shown that IPGs can be exploited to charter forbidden grounds, with the creation of non-linear pH gradients covering the extreme alkaline pH 10-12 gradient. In such basic regions, excellent steady-state patterns of histones and subtilisin mutants have been reported. Different families of histones could be mapped not only in this pH 10-12 interval, but also in 2-D maps exploiting this very alkaline gradient in the first dimension. Although the IPG technique is now a trouble-free, user-friendly technique, some annoying artefacts, producing severe protein smears and precipitation, were very recently reported, but found to be linked to some commercial Immobiline preparations containing up to 5% oligomers. Better quality control on the part of the company producing such chemicals should eliminate even this last source of troubles.
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Affiliation(s)
- P G Righetti
- Department of Agricultural and Industrial Biotechnologies, University of Verona, Italy
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Hermansen LF, Juul J, Sletten K. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and centrifuge blotting: preparation of polypeptides for amino-terminal sequence analysis. Electrophoresis 1996; 17:720-2. [PMID: 8738334 DOI: 10.1002/elps.1150170417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The applicability and reproducibility of a previously described (L. F. Hermansen et al., Electrophoresis 1993, 14, 1302-1306) centrifuge-blotting procedure for capturing subnanomolar amounts of protein on polyvinylidene difluoride membranes for direct Edman degradation was further investigated. Proteins with different molecular masses were centrifuge-blotted onto Immobilon CD membranes. Simultaneous blotting and desalting was achieved with an overall yield of 15-56% after 2 h centrifugation for proteins with a molecular mass of 12-30 kDa. Centrifugation of myoglobin for 6 h resulted in an overall yield of 72%. The subnanomolar amounts obtained were also sufficient to conduct cyanogen bromide cleavage in situ on proteins with blocked NH2-terminus and to generate sequence information.
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Affiliation(s)
- L F Hermansen
- Department of Biochemistry, University of Oslo, Norway
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Patterson SD, Aebersold R. Mass spectrometric approaches for the identification of gel-separated proteins. Electrophoresis 1995; 16:1791-814. [PMID: 8586048 DOI: 10.1002/elps.11501601299] [Citation(s) in RCA: 305] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Rabilloud T, Vincon M, Garin J. Micropreparative one- and two-dimensional electrophoresis: improvement with new photopolymerization systems. Electrophoresis 1995; 16:1414-22. [PMID: 8529607 DOI: 10.1002/elps.11501601234] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To improve the efficiency of one- and two-dimensional electrophoresis for micropreparative purposes, the use of gels polymerized with other initiators than the standard N,N,N',N'-tetramethylethylenediamine (TEMED)/persulfate systems for sodium dodecyl sulfate electrophoresis has been investigated. We show here that the recently described photoinitiator system, composed of methylene blue, toluene sulfinate and diphenyliodonium chloride, leads to a decreased resolution. Resolution can be restored if methylene blue is replaced by riboflavin. Two-dimensional electrophoresis with mg loadings of proteins has also been evaluated with these systems. Independently of the polymerization system, resolution for the first dimension is low with rod gels, increases with gel strips and is further improved when immobilized pH gradients are used. Here too, only the riboflavin/sulfinate/iodonium system results in a resolution that matches the one obtained with the standard TEMED/persulfate system. Gels polymerized with the riboflavin/sulfinate/iodonium system yield better results upon N-terminal microsequencing after blotting than gels polymerized with the standard TEMED/persulfate system.
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Affiliation(s)
- T Rabilloud
- CEA, Laboratoire de Biologie Moléculaire du Cycle Cellulaire, INSERM U309, DBMS/BMCC, CEN-G, Grenoble, France
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Chiari M, Righetti PG, Negri A, Ceciliani F, Ronchi S. Preincubation with cysteine prevents modification of sulfhydryl groups in proteins by unreacted acrylamide in a gel. Electrophoresis 1992; 13:882-4. [PMID: 1483433 DOI: 10.1002/elps.11501301193] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It has been found that the double bond of free, unreacted acrylamide in a gel can react with a free -SH group of proteins, forming a cysteinyl-S-propionamide adduct. When beta-lactoglobulin was incubated at concentration levels lower than those of free acrylamide, left after polymerizing a 5% T, 4% C gel (barely 12 mM), under anaerobic conditions in 0.1 M borate, pH 9.5, for 1 h and then the tryptic digests analyzed by high performance liquid chromatography (HPLC), two new peptides were detected. The two new peaks were recovered and sequenced by the Edman degradation procedure. They correspond to the sequence from Leu-149 to Ile-162. Residue No. 160 was found to be a cysteinyl-S-propionamide reaction product. Interestingly, only this residue, out of a total of 5 Cys residues, had reacted. No other amino acids (including -NH2 terminus and free -NH2 in Lys) reacted with free acrylamide. The addition of free acrylamide to the -SH group could be completely inhibited if: (i) the gel was extensively washed prior to sample application, or (ii) the gel was incubated for 1 h in 100 mM free Cys.
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Affiliation(s)
- M Chiari
- Department of Biomedical Sciences and Technologies, University of Milano, Italy
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Gelfi C, de Besi P, Alloni A, Righetti PG. Investigation of the properties of novel acrylamido monomers by capillary zone electrophoresis. J Chromatogr A 1992. [DOI: 10.1016/0021-9673(92)87140-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ettori C, Righetti PG, Chiesa C, Frigerio F, Galli G, Grandi G. Purification of recombinant human growth hormone by isoelectric focusing in a multicompartment electrolyzer with immobiline membranes. J Biotechnol 1992; 25:307-18. [PMID: 1368806 DOI: 10.1016/0168-1656(92)90163-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recombinant human growth hormone (r-hGH) expressed in Escherichia coli, was 70-80% purified by a combination of ion-exchange chromatography and metal ion affinity chromatography. For the last purification step, a multicompartment electrolyzer was used, containing three compartments delimited by isoelectric membranes and two additional anodic and cathodic chambers. The central compartment was situated between two membranes having isoelectric points (pI) of 5.08 (anodic) and of 5.16 (cathodic), i.e. equidistant from the pI value of hGH (pI 5.12). r-hGH was isoelectric between these two membranes and could not leave the central chamber, while more acidic and more cathodic impurities collected in the two lateral chambers under the influence of the electric field. The r-hGH, thus purified, exhibited a single band by isoelectric focusing (IEF) in immobilized pH gradients (IPG) and gave recoveries greater than 90%. The problem of isoelectric precipitation in a practically ion-free environment was alleviated by focusing in 30% glycerol added with 1% neutral detergent (Nonidet-P40). The latter was eliminated by passage through a Q-Sepharose column after collecting the pI 5.12 band from the electrolyzer. Also the pre-hormone (pre-hGH) can be purified in a similar manner (30% glycerol, 1% Nonidet P-40) between two membranes having pIs 4.77 (anodic) and 4.87 (cathodic) (pre-hGH pI 4.82). This paper demonstrates the possibility of purifying by a focusing process also poorly soluble proteins at the pI.
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Affiliation(s)
- C Ettori
- Department of Biomedical Sciences and Technologies, Univ. Milano, Italy
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Polyacrylamide gel polymerization under non-oxidizing conditions, as monitored by capillary zone electrophoresis. J Chromatogr A 1992. [DOI: 10.1016/0021-9673(92)85058-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Bastyns K, Engelborghs Y. Acrylamide quenching of the fluorescence of glyceraldehyde-3-phosphate dehydrogenase: reversible and irreversible effects. Photochem Photobiol 1992; 55:9-16. [PMID: 1603853 DOI: 10.1111/j.1751-1097.1992.tb04203.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The acrylamide quenching of the tryptophan fluorescence of apo and holo glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was studied. In the case of apo-GAPDH, the steady state fluorescence quenching cannot be described by the classical Stern-Volmer equation: strong cooperative quenching is observed. In the presence of Pi and/or cofactor NAD+, an inaccessible fraction appears. Cooperative quenching is partially suppressed in the presence of Pi and fully absent in the presence of NAD+. The measurements of the fluorescence lifetimes of the holo-enzyme by phasefluorometry allow the resolution of two lifetimes. The long-lived component is quenched by acrylamide, the short-lived component is not. Quenching induces a red shift of the steady state emission peak. The quenching parameters from the lifetime measurements allow the quantitative description of the steady state fluorescence quenching data. In agreement with the observations of Orstan and Gafni (Photochemistry and Photobiology, (1990) 31, 725-731), we find that acrylamide causes a slow, irreversible loss of activity and a reduction of titratable thiol groups when it acts on the apo-enzyme. This inactivation is strongly reduced in the presence of NAD+. We show that this inactivation is also slowed down by the presence of Pi, and that it is accompanied by a loss of the NAD+ binding site. Blocking the thiol groups with 5,5'-dithio-bis-(2-nitrobenzoic acid) does not lead to a protection against the irreversible inactivation by acrylamide, showing that reactions other than thiol modifications are involved in the irreversible effect. A fraction of the inactivation can be reversed by treatment with mercapto-ethanol.
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Affiliation(s)
- K Bastyns
- Laboratory of Chemical and Biological Dynamics, Katholieke Universiteit Leuven, Belgium
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