Molecular Weight of Legumin From Pisum sativum

1980 ◽  
Vol 7 (3) ◽  
pp. 221 ◽  
Author(s):  
RJ Blagrove ◽  
GG Lilley ◽  
R Davey
Keyword(s):  
Molecular Weight ◽  
Recent Literature ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sedimentation Equilibrium ◽  
Pumpkin Seed ◽  
Subunit Molecular Weight ◽  
A Value ◽  
Oligomeric Protein ◽  
Physicochemical Studies ◽  
Pea Seed

There have been many physicochemical studies of legumin, one of the major storage globulins isolated from pea seed. The more recent literature values for the molecular weight of this protein are in the range 390 000-420 000. These results are not consistent with the subunit molecular weight of legumin determined by dodecyl sulfate-polyacrylamide gel electrophoresis, if a hexameric model is assumed. We have measured the molecular weight of a highly purified sample of Pisum legumin by meniscus depletion sedimentation equilibrium and have found a value of 350 000 � 10 000. Since the oligomeric protein is homogeneous with respect to molecular weight, the heterogeneity reported for the subunit polypeptides, using various conditions of electrophoresis, presumably reflect differences in charge and amino acid composition. The molecular weight of legumin is significantly greater than the value of 325 000 found for cucurbitin, the equivalent crystalline protein isolated from pumpkin seed.

Physicochemical Studies of Conglutin γ, a Storage Globulin From Seeds of Lupinus angustifolius

1980 ◽  
Vol 7 (1) ◽  
pp. 1 ◽  
Author(s):  
RJ Blagrove ◽  
JM Gillespie ◽  
GG Lilley ◽  
EF Woods
Keyword(s):  
Molecular Weight ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Optical Rotatory Dispersion ◽  
Sedimentation Equilibrium ◽  
Native Protein ◽  
Equilibrium Studies ◽  
Physicochemical Studies ◽  
Α Helix

Physicochemical studies are reported for conglutin �, the minor globulin isolated from seeds of L. angustifolius cv. Uniwhite. Isoelectric focusing of the native protein in polyacrylamide gel slabs resolved major and minor broad bands near pH 8.0 and 7.8 respectively. Following reduction of disulfide bonds with β-mercaptoethanol in 8 M urea, the smaller polypeptide chain of known sequence focused near pH 6.9 while the larger chain focused near pH 8.0. Sedimentation equilibrium studies showed that the major component in aqueous buffers at neutral pH is a hexamer of molecular weight 280 000 which dissociates to the monomer of molecular weight 47 000 at pH 4.8. The sequence molecular weight of the small subunit polypeptide is 16 517 [Elleman, T.C. (1977). Aust. J. Biol. Sci. 30, 33-45]. The molecular weights determined for the larger chain by sedimentation equilibrium or column chromatography in 6 M guanidine hydrochloride, and by dodecyl sulfate-polyacrylamide gel electrophoresis, were in the range 28 000-30 000. Optical rotatory dispersion and circular dichroism measurements have been used to establish the approximate proportions of α-helix (15%), β-structure (35%), β-turns (18%) and unordered regions (32%) in the native protein. The denaturation curve for guanidine hydrochloride and the proportions of α-helix (50%), β-turns (18%) and unordered regions (32%) in 80 % trifluoroethanol have been determined.

scholarly journals Purification and properties of 6-phosphogluconate dehydrogenase from sheep liver

1969 ◽  
Vol 115 (4) ◽  
pp. 639-643 ◽  
Author(s):  
R. H. Villet ◽  
K. Dalziel
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sedimentation Velocity ◽  
Sedimentation Equilibrium ◽  
Equilibrium Studies ◽  
Phosphogluconate Dehydrogenase ◽  
Sheep Liver ◽  
Equilibrium Sedimentation ◽  
Purification And Properties

A method is described for the isolation of 6-phosphogluconate dehydrogenase from sheep liver. The product appears to be homogeneous in polyacrylamide-gel electrophoresis and in sedimentation-velocity and sedimentation-equilibrium studies in the ultracentrifuge. The molecular weight is estimated as 129000 from equilibrium sedimentation.

Novel Catalatic Proteins of Bakers' Yeast. I. An Atypical Catalase

1973 ◽  
Vol 51 (11) ◽  
pp. 1551-1555 ◽  
Author(s):  
Tony C. M. Seah ◽  
A. R. Bhatti ◽  
J. G. Kaplan
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Native Protein ◽  
Wild Type ◽  
Major Band ◽  
Subunit Molecular Weight ◽  
Purification And Properties

At any stage of growth of a wild-type bakers' yeast, some 20% of the catalatic activity of crude extracts is not precipitable by means of antibody prepared against the typical catalase (catalase T), whose purification and properties have been previously described. Some of this catalatic activity is due to the presence of an atypical catalase (catalase A), a heme protein, with a molecular weight estimated as 170 000 – 190 000, considerably lower than that of the usual catalases (225 000 – 250 000). Preparations of catalase A were found to be homogeneous in the analytical ultracentrifuge and in polyacrylamide gel electrophoresis. Its subunit molecular weight, determined from its iron content, was 46 500, virtually the same as that of the major band obtained in gel electrophoresis in the presence of sodium dodecyl sulfate, suggesting that the native protein is tetrameric. Its specific activity is in the range of those reported for other typical catalases.

scholarly journals Increased membrane binding of erythrocyte catalase in hereditary spherocytosis and in metabolically stressed normal cells

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 113-123 ◽  
Author(s):  
DW Allen ◽  
S Cadman ◽  
SR McCann ◽  
B Finkel
Keyword(s):  
Molecular Weight ◽  
Hereditary Spherocytosis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Membrane Binding ◽  
Sodium Dodecyl ◽  
Protein Band ◽  
Normal Cells ◽  
Calcium Dependent ◽  
Subunit Molecular Weight ◽  
Erythrocyte Catalase

Abstract Normal red blood cell (RBC) membranes were compared with (1) RBC membranes from six patients with hereditary spherocytosis (HS), (2) normal membranes after hemolysis of the RBC in the presence of calcium, or (3) normal membranes after incubation of RBC for 24 hr in phosphate- buffered saline containing calcium without added glucose. When compared with normal controls, polyacrylamide gel electrophoresis with sodium dodecyl sulfate (PAGE SDS) of all three preparations showed an increase in membrane binding of globin and protein band 4.5 (60,000 molecular weight). In an attempt to identify band 4.5, 14 enzymes were assayed in the RBC membranes. Of these, catalase and lactate dehydrogenase were increased in membranes from HS RBC and from normal cells exposed to calcium. Only catalase, however, was present in sufficient quantity and had the correct subunit molecular weight on PAGE SDS and calcium- dependent membrane binding to account for an appreciable portion of 4.5. Caralase was further identified with a component of band 4.5 by double immunodiffusion using a specific anti-catalase antibody.

scholarly journals Purification and structural characterization of a cartilage matrix protein

1981 ◽  
Vol 197 (2) ◽  
pp. 367-375 ◽  
Author(s):  
M Paulsson ◽  
D Heinegård
Keyword(s):  
Molecular Weight ◽  
Matrix Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cartilage Matrix ◽  
Sedimentation Equilibrium ◽  
Intact Protein ◽  
Gel Chromatography ◽  
Guanidinium Chloride ◽  
Cscl Density Gradient

The cartilage matrix protein is a major non-collagenous protein in bovine cartilage. It was purified from a 5 M-guanidinium chloride extract of bovine tracheal cartilage by sequential CsCl-density-gradient centrifugation, gel chromatography in guanidinium chloride and differential precipitation. The molecular weight of the intact protein is 148 000, determined by sedimentation-equilibrium centrifugation. It was dissociated to three subunits of molecular weight 52 000 by reduction of disulphide bonds. The cartilage matrix protein was insoluble in low-salt solutions and behaved abnormally on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The content of cysteine was high, whereas the contents of aromatic amino acids were low. The carbohydrate content was 3.9% (w/w). Glycopeptides obtained after papain digestion were heterogenous on gel chromatography. Asparagine/aspartic acid was enriched in the purified glycopeptides, indicating the presence of N-glycosidic linkages to protein.

scholarly journals Thiol reduction of human α2-macroglobulin. The subunit structure

1972 ◽  
Vol 127 (1) ◽  
pp. 187-197 ◽  
Author(s):  
J. M. Jones ◽  
J. M. Creeth ◽  
R. A. Kekwick
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Sedimentation Equilibrium ◽  
Subunit Structure ◽  
Experimental Conditions ◽  
A Value ◽  
Α2 Macroglobulin ◽  
A Subunit ◽  
Normal Human ◽  
Ph Range

1. Human α2-macroglobulin was prepared from a fraction obtained during the large-scale separation of normal human plasma proteins for clinical use. 2. Sedimentation-equilibrium measurements indicated a molecular weight of 725000. A value of 18.1S was obtained for s020,w. 3. The dissociation that occurs in the pH range 4.5–2.5 and in the region of neutrality in urea-containing solutions is consistent with a dimeric structure of the molecule. 4. The effects of the thiol reagents mercaptoethanol, mercaptoethylamine and N-acetylcysteine were investigated over a range of experimental conditions. Distinct components having sedimentation coefficients of 15, 12 and 8.5S were identified. 5. Conditions were found under which limited reduction with thiol liberated a subunit with a molecular weight approximately one-quarter of that of the intact molecule. This subunit retains the serological specificity of the whole molecule.

scholarly journals Increased membrane binding of erythrocyte catalase in hereditary spherocytosis and in metabolically stressed normal cells

Blood ◽  
1977 ◽  
Vol 49 (1) ◽  
pp. 113-123
Author(s):  
DW Allen ◽  
S Cadman ◽  
SR McCann ◽  
B Finkel
Keyword(s):  
Molecular Weight ◽  
Hereditary Spherocytosis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Membrane Binding ◽  
Sodium Dodecyl ◽  
Protein Band ◽  
Normal Cells ◽  
Calcium Dependent ◽  
Subunit Molecular Weight ◽  
Erythrocyte Catalase

Normal red blood cell (RBC) membranes were compared with (1) RBC membranes from six patients with hereditary spherocytosis (HS), (2) normal membranes after hemolysis of the RBC in the presence of calcium, or (3) normal membranes after incubation of RBC for 24 hr in phosphate- buffered saline containing calcium without added glucose. When compared with normal controls, polyacrylamide gel electrophoresis with sodium dodecyl sulfate (PAGE SDS) of all three preparations showed an increase in membrane binding of globin and protein band 4.5 (60,000 molecular weight). In an attempt to identify band 4.5, 14 enzymes were assayed in the RBC membranes. Of these, catalase and lactate dehydrogenase were increased in membranes from HS RBC and from normal cells exposed to calcium. Only catalase, however, was present in sufficient quantity and had the correct subunit molecular weight on PAGE SDS and calcium- dependent membrane binding to account for an appreciable portion of 4.5. Caralase was further identified with a component of band 4.5 by double immunodiffusion using a specific anti-catalase antibody.

scholarly journals Erythrocruorin from the water-flea Daphnia magna. Quaternary structure and arrangement of subunits

1982 ◽  
Vol 207 (2) ◽  
pp. 297-303 ◽  
Author(s):  
E Ilan ◽  
E Weisselberg ◽  
E Daniel
Keyword(s):  
Molecular Weight ◽  
Daphnia Magna ◽  
Quaternary Structure ◽  
Slow Component ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sedimentation Coefficient ◽  
Sedimentation Equilibrium ◽  
Subunit Structure ◽  
Single Chain

The subunit structure of erythrocruorin from the cladoceran Daphnia magna was studied. The native protein was found to have a sedimentation coefficient (S2(20), w) of 17.9 +/- 0.2 S and a molecular weight, as determined by sedimentation equilibrium, of 494 000 +/- 33 000. Iron and haem determinations gave 0.312 +/- 0.011% and 3.84 +/- 0.04%, corresponding to minimal molecular weights of 17900 +/- 600 and 16 100 +/- 200 respectively. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis gave one band with mobility corresponding to a molecular weight of 31 000 +/- 1 500. The molecular weight of the polypeptide chain determined by sedimentation equilibrium in 6 M-guanidinium chloride and 0.1 M-2-mercaptoethanol is 31 100 +/- 1300. On a molecular-weight basis, Daphnia erythrocruorin is composed of 16 identical polypeptide chains carrying two haem groups each. The native structure is stable between pH5 and 8.5. At alkaline and acidic pH, a gradual decrease in the sedimentation coefficient down to 9.8S occurs. Above pH 10 and below pH4, a slow component with S20, w between 2.7S and 4.0S is observed. The 2.7S, 4.0S and 9.8S species are identified as single-chain subunits, subunit dimers and half-molecules respectively. We propose a model for the molecule composed of 16 2.7S subunits grouped in two layers stacked in an eclipsed orientation, the eight subunits of each layer occupying the vertices of a regular eight-sided polygon. Support for this arrangement is provided from electron microscopy and from analysis of the pH-dissociation pattern.

Anomalous aggregation of Clostridium perfringens enterotoxin under dissociating conditions

1976 ◽  
Vol 22 (9) ◽  
pp. 1410-1414 ◽  
Author(s):  
George L. Enders Jr. ◽  
Charles L. Duncan
Keyword(s):  
Molecular Weight ◽  
Clostridium Perfringens ◽  
Gel Electrophoresis ◽  
Cetyltrimethylammonium Bromide ◽  
Equilibrium Dialysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Binding Studies ◽  
Clostridium Perfringens Enterotoxin ◽  
Subunit Molecular Weight

Polyacrylamide gel electrophoresis of highly purified Clostridium perfringens enterotoxin revealed electrophoretic microheterogeneity of the enterotoxin, apparently because of slight charge differences in the peptides. Detergent gel electrophoresis showed that purified enterotoxin formed high molecular weight aggregates in the presence of both sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide. No conditions capable of inhibiting this phenomenon were found. Although a molecular weight of 35 000 daltons has been reported in the literature, the experimentally determined molecular weight values in the presence of detergents corresponded to multiples of a theoretical subunit molecular weight of 17 500 daltons. Binding studies performed by equilibrium dialysis and ultracentrifugation methods revealed that the enterotoxin bound very small amounts of SDS per gram of protein. The evidence presented indicates possible detergent induced structural alterations of the protein.

Sign in / Sign up

Export Citation Format

Share Document