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 Chemical properties of guinea-pig immunoglobulins γ2G and γM

1970 ◽  
Vol 120 (4) ◽  
pp. 787-795 ◽  
Author(s):  
R. G. Q. Leslie ◽  
S. Cohen
Keyword(s):  
Amino Acid ◽  
Guinea Pig ◽  
Chemical Properties ◽  
Biological Properties ◽  
Extinction Coefficients ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Structural Differences ◽  
Polypeptide Chains

The isolation of guinea-pig immunoglobulins γ1G, γ2G and γM are described and methods for separating the polypeptide chains of each examined. The molecular weights, extinction coefficients and carbohydrate and amino acid compositions of the immunoglobulins and their constituent chains have been analysed. The findings provide a basis for further studies attempting to relate structural differences to distinct biological properties of guinea-pig immunoglobulins.

scholarly journals The Proteins of the Keratin Component of Bird?s Beaks

1976 ◽  
Vol 29 (6) ◽  
pp. 467 ◽  
Author(s):  
MJ Frenkel ◽  
JM Gillespie
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Major Protein ◽  
Major Fraction ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Isoelectric Points ◽  
Related Proteins ◽  
Keratin Proteins ◽  
Similar Amino Acid

Birds' beaks have an outer shell of hard keratin which consists almost entirely of proteins which are very rich in glycine [about 30 residues per 100 residues (residues %)], contain moderate levels of tyrosine and serine (each about 8 residues %), and which have relatively low contents of cystine (about 2�5 residues %), lysine, histidine, isoleucine and methionine. Major protein fractions in the S-carboxymethyl form isolated from the beaks of 'six different orders of birds have similar amino acid compositions, isoelectric points (pH 4�2-4�9) and molecular weights (13 000--14 500). Detailed chromatographic electrophoretic and compositional studies of the proteins of kookaburra beak reveal them to be a family of closely related proteins with only limited heterogeneity, in contrast to mammalian keratin systems. The major kookaburra beak fraction is similar in overall composition and molecular weight to fowl epidermal scale, kookaburra claw and turtle scute proteins and shows some resemblance to reptile claw protein. Beaks also contain small amounts of protein which are distinctly different from the major fraction but which resemble feather keratin proteins in composition and size.

Effect of extractant and molecular size on the optical and chemical properties of soil humic acids

Soil Research ◽  
1969 ◽  
Vol 7 (3) ◽  
pp. 229 ◽  
Author(s):  
JHA Butler ◽  
JN Ladd
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Humic Acids ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Molecular Size ◽  
Carboxyl Content ◽  
Peptide Bonds ◽  
Molecular Weights ◽  
Amino Acid Contents

Humic acids extracted from soil with sodium pyrophosphate have greater proportions of lower molecular weight material, less acid-hydrolysable amino acid nitrogen contents, but greater carboxyl contents and extinction values (260 and 450 nm) than humic acids extracted subsequently from the same sample with alkali. Humic acids extracted with alkali from fresh soil samples have intermediate values. Extinction values at 260 nm are directly correlated with carboxyl contents for a given soil. Different crop histories have no significant effect on the measured properties of the extracted humic acids. An alkali-extracted humic acid has been fractionated by gel filtration into seven fractions of different nominal molecular weight ranges. As the molecular weights of the fractions increase, both aliphatic C-H (based on infrared absorption at 2900 cm-1) and acid-hydrolysable amino acid contents increase, whereas extinction values at 260 nm and carboxyl contents decrease. The infrared spectra of the high molecular weight fractions have peaks at 1650 and 1510 cm-1 which correlate with acid-hydrolysable amino acid contents and which correspond to amide I and II bands of peptide bonds. Alkaline hydrolysis to split peptide bonds eliminates both these peaks. The spectra also have peaks at 1720 and 1210 cm-1 which correlate with the carboxyl content.

scholarly journals α-Crystallin. Fractionation of subunits and sequence studies on an isolated polypeptide

1971 ◽  
Vol 124 (2) ◽  
pp. 345-355 ◽  
Author(s):  
Robert C. Augusteyn ◽  
Abraham Spector
Keyword(s):  
Amino Acid ◽  
Gel Electrophoresis ◽  
Cyanogen Bromide ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Iodoacetic Acid ◽  
Cysteine Residue ◽  
Terminal Sequence ◽  
Amino Acid Compositions ◽  
Molecular Weights

α-Crystallin was carboxymethylated with radioactive iodoacetic acid in the presence of 7.6m-urea and then separated into six major fractions by chromatography on DEAE-cellulose in 7m-urea. Based on the amino acid compositions, specific radioactivities and sodium dodecyl sulphate–gel electrophoresis of the fractions, it was concluded that α-crystallin contains at least four different subunits: DU1A and DU1B, containing no cysteine; a third component represented by DU2B and DU3 containing one cysteine one cysteine residue per subunit; and DU4, which probably contains two residues of cysteine per subunit. Subunit DU1A was shown to be of sufficient purity for sequence studies. Cyanogen bromide cleavage yielded two peptides, CB-1 and CB-2, in approximately equal amounts as expected. The sum of the molecular weights and amino acid compositions of the peptides were both in excellent agreement with the results obtained for subunit DU1A. The amino acid sequence of the first sixteen residues of peptide CB-1 is: Ser-Leu-Thr-Lys-Asp-Phe-Asp-Glu-Val-Asn-Ile-Asp-Val-Ser-His-Phe-. The sequence of the first seventeen residues of peptide CB-2 is: Asp-Ile-Ala-Ile-Ser-His-Pro-Trp-Ile-Arg-Pro-Ser-Phe-Phe-Glu-Phe-His-. The N-terminal sequence of subunit DU1A was shown to be N-acetylmethionine followed by peptide CB-2.

scholarly journals The structural genes for three Drosophila glue proteins reside at a single polytene chromosome puff locus

1983 ◽  
Vol 3 (4) ◽  
pp. 623-634
Author(s):  
T E Crowley ◽  
M W Bond ◽  
E M Meyerowitz
Keyword(s):  
Salivary Gland ◽  
Amino Acid ◽  
Polytene Chromosome ◽  
Larval Instar ◽  
Chemical Properties ◽  
Group Iv ◽  
Group Iii ◽  
Molecular Weights ◽  
Glue Proteins ◽  
Group Ii

The polytene chromosome puff at 68C on the Drosophila melanogaster third chromosome is thought from genetic experiments to contain the structural gene for one of the secreted salivary gland glue polypeptides, sgs-3. Previous work has demonstrated that the DNA included in this puff contains sequences that are transcribed to give three different polyadenylated RNAs that are abundant in third-larval-instar salivary glands. These have been called the group II, group III, and group IV RNAs. In the experiments reported here, we used the nucleotide sequence of the DNA coding for these RNAs to predict some of the physical and chemical properties expected of their protein products, including molecular weight, amino acid composition, and amino acid sequence. Salivary gland polypeptides with molecular weights similar to those expected for the 68C RNA translation products, and with the expected degree of incorporation of different radioactive amino acids, were purified. These proteins were shown by amino acid sequencing to correspond to the protein products of the 68C RNAs. It was further shown that each of these proteins is a part of the secreted salivary gland glue: the group IV RNA codes for the previously described sgs-3, whereas the group II and III RNAs code for the newly identified glue polypeptides sgs-8 and sgs-7.

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.

Comparison of hemolysins of Vibrio cholerae non-O1 and Vibrio hollisae with thermostable direct hemolysin of Vibrio parahaemolyticus

1988 ◽  
Vol 34 (12) ◽  
pp. 1321-1324 ◽  
Author(s):  
Myonsun Yoh ◽  
Takeshi Honda ◽  
Toshio Miwatani
Keyword(s):  
Amino Acid ◽  
Vibrio Cholerae ◽  
Vibrio Parahaemolyticus ◽  
Antigenic Determinants ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Time Dependencies ◽  
Thermostable Direct Hemolysin ◽  
Effects Of Temperature ◽  
Vibrio Hollisae

Hemolysin (Vh-rTDH) produced by Vibrio hollisae and hemolysin (NAG-rTDH) produced by Vibrio cholerae non-O1 were characterized and compared with hemolysin (Vp-TDH) produced by Vibrio parahaemolyticus. These three hemolysins are each composed of two subunits and have similar, but not identical, molecular weights. The amino acid compositions of Vp-TDH and NAG-rTDH are similar, but are different from that of Vh-rTDH. The three hemolysins showed similar lethal toxicities to mice. The effects of temperature on hemolysis and the time dependencies of hemolysis by the three hemolysins were similar. The three were concluded to be immunologically related, but not identical, and to have common and also unique antigenic determinants.

Hämoproteinoide mit peroxidatischer und katalatischer Aktivität / The Peroxidatic and Catalatic Activity of Hemoproteinoids

1971 ◽  
Vol 26 (2) ◽  
pp. 144-148 ◽  
Author(s):  
Klaus Dose ◽  
Laila Zaki
Keyword(s):  
Amino Acid ◽  
Horseradish Peroxidase ◽  
Substrate Specificity ◽  
Amino Acid Composition ◽  
Lysine Content ◽  
Molecular Weights ◽  
Synthetic Materials ◽  
Isoelectric Points ◽  
The Many ◽  
Anaerobic Environment

Hemoproteinoids related to contemporary porphyrin-dependent peroxidases were synthesized under simple conditions. The peroxidative activity of hematin increased by a factor of 50 if the hematin was bound to proteinoids whereas the catalatic activity of hematin decreased rather under the same conditions. The peroxidative activity of hemoproteinoids particularly increased with their lysine content whereas the catalatic activity especially decreased in proteinoids with high phenylalanine content. The isoelectric points of the lysine-rich peroxidic hemoproteinoids were about 8. Their relatively broad pH-activity optimum was about pH 7.0. The molecular weights were a little below 20 000. Hematin content and amino acid composition of the synthetic materials were varied greatly. The substrate specificity appeared as broad as that of biogenous peroxidases, e. g., horseradish peroxidase. Among the many substrates was NADH. The possible importance of the peroxidative oxidation of NADH-type coenzymes by primitive heterotrophic organisms or prebiological systems in an anaerobic environment is discussed.

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