scholarly journals INCORPORATION OF SULFATE INTO THE CAPSULAR POLYSACCHARIDE OF THE RED ALGA PORPHYRIDIUM

1972 ◽  
Vol 54 (2) ◽  
pp. 399-407 ◽  
Author(s):  
J. Ramus ◽  
S. T. Groves
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Gel Electrophoresis ◽  
Capsular Polysaccharide ◽  
Cetylpyridinium Chloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Red Alga ◽  
Rapid Labeling ◽  
Hydrolysis Of ◽  
Porphyridium Aerugineum

The accumulation of sulfate-35S by Porphyridium aerugineum cells and subsequent appearance of solubilized capsular polysaccharide-35S in the growth medium were examined The uptake of label by the cells was largely light dependent. Pulse-chase experiments using log phase cells revealed a rapid labeling of solubilized capsular polysaccharide, recovered from the medium as the cetylpyridinium chloride precipitate Polyacrylamide gel electrophoresis of the polysaccharide-35S showed the sulfate to be firmly bound to an immobile fraction. Sephadex chromatography revealed the molecular weight of the polysaccharide to be in excess of 2 x 105. Acid hydrolysis of the polysaccharide-35S released sulfate-35S ion as evidenced by radioautography of thin layer chromatographs Preliminary electron microscope evidence suggests that the synthesis, movement, and deposition of the capsular polysaccharide on the cell surface are Golgi complex-mediated processes

scholarly journals Organospecific reactions of yellow lupin seedlings to lead

2014 ◽  
Vol 66 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Jarosław Gzyl ◽  
Roman Przymusiński ◽  
Adam Woźny
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Gel Electrophoresis ◽  
Cell Walls ◽  
Polyacrylamide Gel Electrophoresis ◽  
Lupinus Luteus ◽  
Root Tip ◽  
Yellow Lupin ◽  
Transmission Electron ◽  
Slight Amount

Changes caused by lead, supplied in the form of Pb(NO3)2, in roots and hypocotyls of 4 day old yellow lupin (<em>Lupinus luteus</em> L. cv. <em>ventus</em>) seedlings have been analyzed using a transmission electron microscope and polyacrylamide gel electrophoresis (PAGE). The cells of all examined parts of the roots growing in the presence of Pb<sup>2+</sup> contained many lead deposits (mainly in the cell walls and vacuoles) and the increased amount of polypeptides of molecular weight close to 16 kDa have been observed. Similar changes were detected in the area of hypocotyl adjoining the root. However, in upper regions of the hypocotyl only a slight amount of lead deposits was visible and the 16 kDa polypeptide content was comparable to the control cells. The obtained results indicate a relationship between the presence of lead deposits in cells and accumulation of polypeptides of - 16 kDa. The results seem also to indicate that in the analyzed parts of the seedlings, both the amount of accumulated polypeptides of MW - 16 kDa and the amount of lead decreased from root tip to hypocotyl.

Irreversible heat denaturation of bovine α-lactalbumin

1986 ◽  
Vol 53 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Lesley C. Chaplin ◽  
Richard L. J. Lyster
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Heat Denaturation ◽  
Two Dimensional ◽  
Native Protein ◽  
Denatured Protein ◽  
Hydrolysis Of

SUMMARYThe irreversible heat denaturation of α-lactalbumin (α-la) in 0·1 M-phosphate, pH 7·0, at 100 °C was studied using polyacrylamide-gel electrophoresis (PAGE). PAGE revealed two groups of bands, one moving faster than native α-la and one slower, in addition to some denatured protein which remained at the origin and some residual native α-la. The faster group had unchanged molecular weight, but an increase in charge, partly due to hydrolysis of glutamine and asparagine residues. The slower group was shown by two-dimensional sodium dodecyl sulphate-PAGE to be oligomers of denatured α-la; formation of the smaller oligomers preceded the larger ones. The oligomers reverted to monomers in the presence of dithiothreitol, showing that they were disulphide-linked aggregates of denatured α-la. Immuno-blots of the gels showed that both fast and slow groups of bands had irreversibly lost most of the antigenicity of the native protein.

scholarly journals The composition and the structure of bacterioferritin of Escherichia coli

1981 ◽  
Vol 197 (1) ◽  
pp. 171-175 ◽  
Author(s):  
J Yariv ◽  
A J Kalb ◽  
R Sperling ◽  
E R Bauminger ◽  
S G Cohen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Electron Microscope ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Iron Compound ◽  
Protein Subunit ◽  
Electron Dense Core

Bacterioferritin isolated from Escherichia coli is of two kinds: a protein containing a polynuclear iron compound, the bacterioferritin proper and a protein free of the polynuclear iron compound, the apo-bacterioferritin. Bacterioferritin of both kinds is characterized by absorption maxima at 417,530 and 560 nm, contributed by protohaem IX. Single crystals of bacterioferritin of the space group I432 suggest that the molecule is made up of 24 identical subunits related by a cubic point symmetry. The molecular weight of the protein subunit, as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, is 15000. In the electron microscope the bacterioferritin molecule appears to be a sphere of 9.5 nm (95 A) diameter composed of a negatively staining outer shell and an inner electron-dense core of 6 nm (60 A) diameter.

Purification and Characterization of an Unusual Aminopeptidase From Pea Seeds

1980 ◽  
Vol 7 (2) ◽  
pp. 131 ◽  
Author(s):  
JB Caldwell ◽  
LG Sparrow
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sulfhydryl Group ◽  
Purification And Characterization ◽  
Apparent Homogeneity ◽  
Pea Seeds ◽  
Hydrolysis Of

An aminopeptidase with specificity for N-terminal glutamic and aspartic acid residues has been purified to apparent homogeneity from pea seeds (Pisum sativum cv. Greenfeast). It also catalyses the hydrolysis of the glutaryl-phenylalanine bond of the synthetic chymotrypsin substrate glutaryl- L-phenylalanine p-nitroanilide. The native enzyme, which has a molecular weight of approximately 500 000, gives a single band on polyacrylamide gel electrophoresis but two major bands when subjected to electrophoresis in the presence of sodium dodecyl sulfate after reduction. Its behaviour with various inhibitors suggests that a sulfhydryl group is important for its activity.

Binding specificity and reactivity studies on a broad-specificity β-glycosidase from porcine kidney

1988 ◽  
Vol 66 (8) ◽  
pp. 830-838 ◽  
Author(s):  
R. E. Huber ◽  
R. L. Brockbank
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Porcine Kidney ◽  
Hydrolysis Of ◽  
Broad Specificity ◽  
Native Molecular Weight

A broad-specificity β-glycosidase from porcine kidney was purified to homogeneity. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis showed that it had a monomeric molecular weight of 55 000–60 000. Gel filtration showed a native molecular weight of about 115 000. These data imply that the native enzyme is a dimer. The enzyme can catalyze the hydrolysis of β bonds between glycosides and 4-methylumbelliferone or nitrophenol yielding D-fucopyranose, D-galactopyranose, D-glucopyranose, D-xylopyranose, and D-mannopyranose and of α bonds to yield L-arabinopyranose. This is the first study that shows a mammalian broad-specificity cytosolic β-glycosidase carrying out a reaction with a β-D-mannopyranoside. The nature of the broad specificity was studied with inhibitors. Similar inhibitor constants were found regardless of whether the substrate was a β-D-glucopyranoside or a β-D-galactopyranoside, so the enzyme probably has only one binding site with a broad specificity. The enzyme prefers to bind compounds with an axial hydroxyl at the 2 position and an equatorial hydroxyl at the 4 position; the 3 position does not affect binding significantly. The hydroxyl at the 6 position affects binding, but binding at that position depends on the configurations at the 2 and 4 positions. Thus, there must be some interactions between these three positions (2, 4, and 6). Lactones are also good inhibitors and this may relate to strain effects.

Configuration of Flagellar Microtubule Subunits

1974 ◽  
Vol 15 (3) ◽  
pp. 495-511
Author(s):  
F. D. WARNER ◽  
I. MEZA
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Electron Microscope ◽  
High Resolution ◽  
Gel Electrophoresis ◽  
Strongylocentrotus Purpuratus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Tubulin Dimer ◽  
Tubulin Subunit ◽  
Negative Staining Electron Microscopy

Microtubule protofilaments and their subunits isolated from sperm flagellar doublet tubules of the sea urchin Strongylocentrotus purpuratus were examined by analytical biochemistry and high-resolution negative staining electron microscopy. All microtubule (tubulin) fractions show 2 polypeptide bands (α and β tubulins) in an approximate 1:1 ratio on urea-polyacrylamide gel electrophoresis. Heat (37 °C)-solubilized microtubules yield a protein fraction containing the tubulin dimer of molecular weight 115000 Daltons. The dimeric tubulin subunit, as seen in the electron microscope, has an overall size of about 3.5 x 8 nm and appears to have the configuration of a figure 8 because of stain penetration into the centre of each of its 2 halves (figure os). Isolated protofilaments (3.5 ± 0.3 nm thick) can each be resolved into 2 subfilaments (1.7 ± 0.2 nm thick). The 2 subfilaments have periodic lateral associations resulting in the basic 4-nm subunit repeat (figure o) along the protofilament. Examination of collapsed and solubilizing protofilaments shows the figure 8 (dimeric) subunits separating at random along the protofilaments. We conclude that the tubulin dimer must be composed of either elongated or bilobed monomers which result in the figure 8 configuration and hence the 2-stranded appearance of the protofilaments.

scholarly journals The structure and mechanism of stem bromelain. Evaluation of the homogeneity of purified stem bromelain, determination of the molecular weight and kinetic analysis of the bromelain-catalysed hydrolysis of N-benzyloxycarbonyl-l-phenylalanyl-l-serine methyl ester

1974 ◽  
Vol 143 (3) ◽  
pp. 575-586 ◽  
Author(s):  
Christopher W. Wharton
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Methyl Ester ◽  
Gel Electrophoresis ◽  
Ph Dependence ◽  
Polyacrylamide Gel Electrophoresis ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Stem Bromelain ◽  
Hydrolysis Of

1. Purified stem bromelain (EC 3.4.22.4) was eluted from Sephadex G-100 as a single peak. The specific activity across the elution peak was approximately constant towards p-nitrophenyl hippurate but increased with elution volume with N2-benzoyl-l-arginine ethyl ester as substrate. 2. The apparent molecular weight, determined by elution analysis on Sephadex G-100, is 22500±1500, an anomalously low value. 3. Purified stem bromelain was eluted from CM-cellulose CM-32 as a single peak and behaved as a single species during column electrophoresis on Sephadex G-100. 4. Purified stem bromelain migrates as a single band during polyacrylamide-gel electrophoresis under a wide variety of conditions. 5. The molecular weight determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate is 28500±1000. 6. Sedimentation-velocity and equilibrium-ultracentrifugation experiments, under a variety of conditions, indicate that bromelain is an apparently homogeneous single peptide chain of mol.wt. 28400±1400. 7. The N-terminal amino acid composition is 0.64±0.04mol of valine and 0.36±0.04mol of alanine per mol of enzyme of mol.wt. 28500. (The amino acid recovery of the cyanate N-terminal amino acid analysis was standardized by inclusion of carbamoyl-norleucine at the cyclization stage.) 8. The pH-dependence of the Michaelis parameters of the bromelain-catalysed hydrolysis of N-benzyloxycarbonyl-l-phenylalanyl-l-serine methyl ester was determined. 9. The magnitude and pH-dependence of the Michaelis parameters have been interpreted in terms of the mechanism of the enzyme. 10. The enzyme is able to bind N-benzyloxycarbonyl-l-phenylalanyl-l-serine methyl ester relatively strongly but seems unable to make use of the binding energy to promote catalysis.

Heterozygous Abnormal Fibrinogen Osaka III with the Replacement of γ Arginine-275 by Histidine Has an Apparently Higher Molecular Weight γ-Chain Variant

1992 ◽  
Vol 68 (05) ◽  
pp. 534-538 ◽  
Author(s):  
Nobuhiko Yoshida ◽  
Shingi Imaoka ◽  
Hajime Hirata ◽  
Michio Matsuda ◽  
Shinji Asakura
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Tetraacetic Acid ◽  
Fibrin Monomer ◽  
Sds Page ◽  
Thrombotic Tendency ◽  
Chain Variant

SummaryCongenitally abnormal fibrinogen Osaka III with the replacement of γ Arg-275 by His was found in a 38-year-old female with no bleeding or thrombotic tendency. Release of fibrinopeptide(s) by thrombin or reptilase was normal, but her thrombin or reptilase time in the absence of calcium was markedly prolonged and the polymerization of preformed fibrin monomer which was prepared by the treatment of fibrinogen with thrombin or reptilase was also markedly defective. Propositus' fibrinogen had normal crosslinking abilities of α- and γ-chains. Analysis of fibrinogen chains on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the system of Laemmli only revealed the presence of abnormal γ-chain with an apparently higher molecular weight, the presence of which was more clearly detected with SDS-PAGE of fibrin monomer obtained by thrombin treatment. Purified fragment D1 of fibrinogen Osaka III also seemed to contain an apparently higher molecular weight fragment D1 γ remnant on Laemmli gels, which was digested faster than the normal control by plasmin in the presence of [ethy-lenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA).

Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Polyacrylamide Gel ◽  
Cleavage Pattern ◽  
Purification And Characterization ◽  
Double Immunodiffusion ◽  
The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

Sign in / Sign up

Export Citation Format

Share Document