All that glisters is not gold: The physical basis of protein coloration in silver-stained gels

1987 ◽  
Vol 45 ◽  
pp. 940-941
Author(s):  
A.C. Steven ◽  
M.E. Bisher ◽  
M. Harrington ◽  
C.R. Merril
Keyword(s):  
Silver Staining ◽  
Gel Electrophoresis ◽  
Chemical Properties ◽  
Physical Basis ◽  
Polyacrylamide Gels ◽  
Molecular Weights ◽  
Coomassie Blue ◽  
Analytical Potential ◽  
Isoelectric Points

The introduction of silver-staining to detect electrophoretically separated proteins in polyacrylamide gels has provided a method that, with the most responsive proteins, is more sensitive by a factor of ∼100 than Coomassie Blue, the most commonly used organic stain. With silver staining, most proteins take on a brownish hue. However, under appropriate conditions, certain proteins have been found to exhibit distinct and vivid colors. Yellow, blue, red and green bands have all been observed. Colorability is a property with considerable analytical potential, in that it may become possible to infer chemical properties of proteins on the basis of their propensities for coloration upon silver-staining. Such information would considerably enhance the analytical capabilities of gel electrophoresis, which for the most part have been restricted to estimates of molecular weights and isoelectric points. To help realize this potential, we have investigated the physical basis of the colorability of proteins.

Analytical electrofocusing and two-dimensional electrophoresis of proteins extracted from the mycelia of aggressive and nonaggressive strains of Ophiostoma ulmi

1986 ◽  
Vol 64 (9) ◽  
pp. 2073-2081 ◽  
Author(s):  
Robert S. Jeng
Keyword(s):  
Dutch Elm Disease ◽  
Two Dimensional ◽  
Polyacrylamide Gels ◽  
Ophiostoma Ulmi ◽  
Two Dimensional Electrophoresis ◽  
Coomassie Blue ◽  
Isoelectric Points ◽  
Additional Protein ◽  
Dimensional Electrophoresis ◽  
Electrophoresis Of Proteins

Soluble mycelial proteins from Ophiostoma ulmi (Buism.) Nannf., the causal agent of Dutch elm disease, were separated by analytical electrofocusing and two-dimensional electrophoresis in polyacrylamide gels. Results showed the aggressive and nonaggressive strains of this pathogen each had about 60 Coomassie blue stained bands having isoelectric points from 3 to 7. Both strains of this fungus had their own characteristic electrofocusing patterns. Nonaggressive isolate S116, for example, lacked two protein bands, one near the anode and one near the cathode, but it had five additional protein bands distributed from pH 4 to 6. Two-dimensional electrophoresis of total soluble proteins depicted that there were 36 proteins found to be specific for the nonaggressive isolate S116 and 12 proteins for the aggressive isolate RR2.

Characterization of PIG Platelet Granule Proteins

1979 ◽  
Author(s):  
M.H. Fukami ◽  
J.L. Daniel ◽  
J.S. Bauer
Keyword(s):  
Gel Electrophoresis ◽  
Plasma Membranes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Dense Granule ◽  
Release Mechanism ◽  
Molecular Weights ◽  
Dense Granules ◽  
Coomassie Blue ◽  
Pas Staining

Platelet granules contain glycoproteins similar to those found in platelet membranes (Hagen et al , BBA , 445, 21 4 , 1 976 ). Pig platelet granule fractions enriched in mitochondria, α-granules or dense granules were analyzed by SDS Polyacrylamide gel electrophoresis to determine if there are differences among the organelles. In a reduced system (5Ϊ OTT) the proteins of the ï-granules and dense granules showed staining patterns with Coomassie blue that were distinctly different from whole platelets, isolated membranes or mitochondria. In the granules about 10 to 12 bands with less mobility than actin were visualized. Staining with PAS was obtained in bands with apparent molecular weights of 250, 225, 185, 170, 150, 120, 55, 4B and 40 K. The 185 K band appeared to be the same as “thrombin sensitive protein”. The mobility of the 55 and 48 K hands were identical with the B (B) and γ-bands of bovine fibrinogen. The PAS staining of the granule components was more intense than that of whole platelets for the same amount of protein, indicating that granule membranes may be as rich in glycoproteins as external plasma membranes. With both PAS and Coomassie blue, the a-granule and dense granule staining patterns were almost identical. This observation may be relevant to recent studies which showed that both granule types exhibited similar release characteristics, suggesting that they share a common release mechanism. NIH-JSPHS Grant No. 14217

scholarly journals Variations in the Methionine-rich Protein Composition of the Genus Arachis1

1984 ◽  
Vol 11 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Sheikh M. Basha ◽  
Sunil K. Pancholy
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Protein Composition ◽  
Electrophoretic Analysis ◽  
Two Dimensional ◽  
Weight Group ◽  
Two Dimensional Gel Electrophoresis ◽  
One Dimensional ◽  
Molecular Weights ◽  
Isoelectric Points

Abstract Methionine-rich proteins (MRP) from seeds of different species of the Genus Arachis were isolated and analyzed by gel electrophoresis to detect possible compositional differences. One-dimensional gel electrophoretic analysis showed presence of quantitative and qualitative variations among the MRP-fractions. Following two-dimensional gel electrophoresis, the MRP-fractions were found to contain three groups of polypeptides with apparent molecular weights of approximately 21,000; 19,000 and 16,000, and isoelectric points between 5.1 and 5.8. Within each molecular weight group the number of polypeptides varied between 1 and 3.

scholarly journals A new variant of the alpha subunit of spectrin in hereditary elliptocytosis

Blood ◽  
1987 ◽  
Vol 69 (2) ◽  
pp. 473-478 ◽  
Author(s):  
S Lambert ◽  
S Zail
Keyword(s):  
Gel Electrophoresis ◽  
Alpha Subunit ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Tryptic Peptides ◽  
Structural Variant ◽  
Hereditary Elliptocytosis ◽  
Coomassie Blue ◽  
New Variant ◽  
Isoelectric Points

Abstract A kindred is described in which two brothers with a poikilocytic variant of hereditary elliptocytosis (HE) were found to have a defect of spectrin dimer association and a decreased spectrin-band 3 ratio. Two-dimensional gel electrophoresis of limited tryptic digests of their spectrin revealed decreased amounts of the alpha I domain when compared with control digests and the appearance of two major peptides with mol wts of 43,000 and 42,000 and isoelectric points (5.75 to 5.85) more basic than the alpha I domain. Tryptic digests of spectrin from the asymptomatic mother of the two brothers were normal. Immunoblots of the two-dimensional gels using an antiserum to the alpha I domain revealed that the 43,000- and 42,000-dalton peptides were derived from the alpha I domain, along with a series of lower mol wt peptides, some of which were below the detection limits of Coomassie blue-stained gels. Limit chymotryptic maps of 125I-labeled tryptic peptides confirmed that the 43,000- and 42,000-dalton peptides were derived from the alpha I domain. This kindred represents a new structural variant of spectrin in HE in that the major abnormal tryptic peptides derived from the alpha I domain have lower mol wts and more basic isoelectric points than hitherto described.

Isoelectric points and molecular weights of salt-extractable ribosomal proteins

1976 ◽  
Vol 54 (12) ◽  
pp. 1029-1033 ◽  
Author(s):  
M Saleem ◽  
Burr Atkinson
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Molecular Weights ◽  
Isoelectric Points ◽  
Acidic Proteins ◽  
Gel Isoelectric Focusing ◽  
Liver Ribosomes

Rat liver ribosomes prepared in low salt buffer contain basic and acidic proteins not found on ribosomes washed in high salt buffer. Proteins extracted from liver ribosomes by 500 mM KCl were characterized by acid urea–polyacrylamide gel electrophoresis, sodium dodecyl sulfate – polyacrylamide gel electrophoresis and gel isoelectric focusing. The salt-solubilized proteins contain 12 polypeptides with a molecular weight over 67 000, several polypeptides with molecular weights less than 67 000, and three polypeptides whose molecular weight exceeded 130 000. Ten to 12 of the proteins were basic, and about 24 acidic proteins were partially or wholly extracted from the ribosomes. Four of the acidic proteins have isoelectric points less than 4.5.

scholarly journals A comparison of the physical and chemical properties of four cytochromes c from Azotobacter vinelandii

1973 ◽  
Vol 135 (4) ◽  
pp. 617-630 ◽  
Author(s):  
Wilbur H. Campbell ◽  
William H. Orme-Johnson ◽  
Robert H. Burris
Keyword(s):  
Amino Acid ◽  
Spectral Properties ◽  
Azotobacter Vinelandii ◽  
Chemical Properties ◽  
Protein Cleavage ◽  
Separation And Purification ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Cytochromes C ◽  
Isoelectric Points

1. A modified method for the separation and purification of four cytochromes c from Azotobacter vinelandii is described. Two new cytochromes c have been purified and are designated cytochromes c(551) and c(555). 2. Additional evidence is presented to establish the dihaem nature of cytochrome c4. Ultracentrifugation data indicated similar molecular weights for the native and the denatured protein. Cleavage with CNBr yielded seven peptides; the amino acid compositions of the purified peptides were determined. Only one haem peptide was recovered. 3. Cytochromes c(551) and c(555) were characterized as acidic proteins of molecular weights about 12000. The spectral properties, isoelectric points, ‘maps’ of peptides from CNBr cleavage and amino acid compositions were determined for these two proteins. 4. The spectral properties, isoelectric points, molecular weights, CNBr peptide ‘maps’, amino acid compositions, relative oxidation–reduction potentials and e.p.r. (electron-paramagnetic-resonance) spectra of the four cytochromes c were compared. Cytochrome c4 and cytochrome c(551) appear to be distinct proteins. The distinction between cytochromes c5 and c(555) was not as clear, and our data are inadequate to establish firmly that they are distinct proteins. 5. The dihaem nature of cytochrome c4 is evident in its e.p.r. spectrum. The e.p.r. spectra are similar to the spectra of mammalian cytochromes c.

scholarly journals Lyt-2 glycoprotein is synthesized as a single molecular species.

1983 ◽  
Vol 157 (1) ◽  
pp. 365-370 ◽  
Author(s):  
E Rothenberg ◽  
D Triglia
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Cell Surface ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Two Dimensional ◽  
Post Translational Modification ◽  
Molecular Weights ◽  
Gradient Electrophoresis ◽  
Isoelectric Points

We investigated the possibility that the Lyt-2 molecules made by uncloned mouse T lymphocytes would show variable primary structures like those of immunoglobulins. Newly synthesized Lyt-2/3 complexes were found to include only two major components, both discrete glycoproteins with apparent molecular weights of 31,000 (31 K) and 35,000 (35 K). When products of Lyt-2.1 and Lyt-2.2 thymocytes were compared by two-dimensional nonequilibrium pH gradient electrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis, the isoelectric points of the 35 K molecules were different; thus, the 35 K component was likely to be encoded by the Lyt-2 locus itself. However, the 35 K molecules made by any one genotype were homogeneous in charge as well as in size. The homogeneity was obscured rapidly by post-translational modification. Most strikingly, within 30 min of initial synthesis, these processing events generated the conspicuous array of microheterogeneous products that form the "38 K" component of cell-surface Lyt-2/3.

Effect of thyrotropin on the phosphorylation of thyroid chromosomal proteins

1979 ◽  
Vol 57 (6) ◽  
pp. 523-528 ◽  
Author(s):  
Yew Phew See ◽  
G. N. Burrow ◽  
C. C. Liew
Keyword(s):  
Quantitative Analysis ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Two Dimensional ◽  
Chromosomal Proteins ◽  
One Dimensional ◽  
Molecular Weights ◽  
Ph Values ◽  
Isoelectric Points ◽  
Tsh Stimulation

Thyrotropin (TSH) stimulated the phosphorylation of histone H1 in calf thyroid slices but had no effect on other classes of histones. Phosphorylation of total phenol-soluble nonhistone chromosomal proteins was not affected by incubation with TSH. However, when these phenol-soluble nonhistone chromosomal proteins were analysed by two-dimensional gels involving isoelectrofocusing and dodecyl sulfate – polyacrylamide gel electrophoresis, TSH was shown to stimulate the phosphorylation of two specific groups of phosphoproteins with molecular weights between 35 000 and 45 000 and isoelectric points at pH values of 5.4–6.0. This increase in phosphorylation with TSH stimulation was confirmed by quantitative analysis of one-dimensional isoelectrofocusing gels.

scholarly journals Die Trennung der Hämolymphe-Proteine bei Vorpuppen und Puppen der Galleria mellonella L. mittels Gel-Filtration auf Sephadex G-200, Bestimmung ihrer isoelektrischen Punkte und ihrer Molekulargewichte / Separation of Haemolymph Proteins of Prepuae and Pupae of Galleria mellonella L. by means of Gel Filtration on Sephadex 200, Determination of their Isoelectric Points and their Molecular Weights

1969 ◽  
Vol 24 (6) ◽  
pp. 732-740 ◽  
Author(s):  
Milan Marek
Keyword(s):  
Gel Electrophoresis ◽  
Galleria Mellonella ◽  
Gel Filtration ◽  
Starch Gel Electrophoresis ◽  
Molecular Weights ◽  
Isoelectric Points ◽  
Starch Gel ◽  
The Individual ◽  
Naphthyl Acetate

Gel filtration on Sephadex G-200 was carried out on haemolymph proteins of prepupae. ligatured prepupae, male and female pupae and cooled pupae of Galleria mellonella L.The proteins were separated into two main fractions. The esterase activity of the eluated haemolymph was determined by means of beta-naphthyl acetate after filtration.After elution the samples were condensed and additionally separated on horizontal starch-gel electrophoresis.The “cooling protein” of pupae and the “ligature protein” of ligatured larvae of Galleria mellonella were shown by means of starch-gel electrophoresis to be new proteins, so far not described.The isoelectric point and molecular weight were determined for the individual protein fractions.They were then stained with amido black 10 B for the proof of proteins, and with alpha-naphthyl butyrate with Fast-Blue BB salt for the identification of esterases.

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