Cellulolytic enzyme system of Acetivibrio cellulolyticus

1981 ◽  
Vol 27 (3) ◽  
pp. 288-294 ◽  
Author(s):  
J. N. Saddler ◽  
A. W. Khan

Polyacrylamide gel electrophoresis of the cellulolytic system from culture supernates of Acetivibrio cellulolyticus showed the presence of four major enzymes: a β-glucosidase, an exoglucanase, and two endoglucanases. The relative proportions of these enzymes in the culture supernate were affected by the nature of the cellulosic substrate and by the length of the incubation period. The molecular weights of the cellulolytic enzymes were β-glucosidase, 81 000; exoglucanase, 38 000; endoglucanase C2, 33 000; and endoglucanase C3, 10 400, as estimated by their electrophoretic mobilities relative to proteins of known molecular weight. Treatment of the high molecular weight endoglucanase with SDS–mercaptoethanol led to reversible dissociation of the enzyme into polypeptide subunits similar to the low molecular weight endoglucanase. Endoglucanase activity could be assayed for directly using a novel method of incorporating carboxymethyl cellulose in the polyacrylamide gels. The molecular weights and functions of these enzymes are compared with those detected in culture filtrates of various fungi.

1979 ◽  
Vol 177 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Gabriel M. Umezurike

1. Filtrates from cultures of different ages of Botryodiplodia theobromae Pat. were fractionated by gel filtration, ion-exchange chromatography and polyacrylamide-gel electrophoresis. 2. Five cellulases (C1, C2, C3, C4 and C5) were found, and their molecular weights, estimated by gel filtration, were 46000–48000 (C1), 30000–35000 (C2), 15000–18000 (C3), 10000–11000 (C4) and 4800–5500 (C5). 3. Cellulase C5 was absent from old culture filtrates. 4. Cellulase C1 had little or no activity on CM-cellulose (viscometric assay), but degraded cotton flock and Whatman cellulose powder to give cellobiose only. 5. The other components (C2–C5) produced cellobiose and smaller amounts of glucose and cellotriose from cellulosic substrates and were more active in lowering the viscosity of CM-cellulose. 6. The ratio of activities assayed by viscometry and by the release of reducing sugars from CM-cellulose increased with decrease in the molecular weights of cellulases C2–C5. 7. Cellobiose inhibited the activities of the cellulases, but glucose stimulated at low concentrations although it inhibited at high concentrations. 8. A high-molecular-weight β-glucosidase (component B1, mol.wt. 350000–380000) predominated in filtrates from young cultures, but a low-molecular-weight enzyme (B4, mol.wt. 45000–47000) predominated in older filtrates. 9. Intermediate molecular species of β-glucosidase (B2, mol.wt. 170000–180000; B3, mol.wt. 83000–87000) were also found. 10. Cellulases C2–C5 acted in synergism with C1, particularly in the presence of β-glucosidase.


1983 ◽  
Vol 59 (1) ◽  
pp. 81-103 ◽  
Author(s):  
R. Crossley ◽  
D.V. Holberton

Proteins from the axonemes and disc cytoskeleton of Giardia lamblia have been examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. In addition to tubulin and the 30 X 10(3) molecular weight disc protein, at least 18 minor components copurify with the two major proteins in Triton-insoluble structures. The most prominent minor bands have the apparent molecular weights of 110 X 10(3), 95 X 10(3) and 81 X 10(3). Protein of 30 X 10(3) molecular weight accounts for about 20% of organelle protein on gels. In continuous 25 mM-Tris-glycine buffer it migrates mostly as a close-spaced doublet of polypeptides, which are here given the name giardins. Giardia tubulin and giardin have been purified by gel filtration chromatography in the presence of sodium dodecyl sulphate. Well-separated fractions were obtained that could be further characterized. Both proteins are heterogeneous when examined by isoelectric focusing. Five tubulin chains were detected by PAGE Blue 83 dye-binding after focusing in a broad-range ampholyte gel. Giardin is slightly less acidic than tubulin. On gels it splits into four major and four minor chains with isoelectric points in the pI range from 5.8 to 6.2. The amino acid composition of the giardin fraction has been determined, and compared to Giardia tubulin and a rat brain tubulin standard. Giardins are rich in helix-forming residues, particularly leucine. They have a low content of proline and glycine; therefore they may have extensive alpha-helical regions and be rod-shaped. As integral proteins of disc microribbons, giardins in vivo associate closely with tubulin. The properties of giardins indicate that in a number of respects - molecular size, charge, stoichiometry - their structural interaction with tubulin assemblies will be different from other tubulin-accessory protein copolymers studied in vitro.


1999 ◽  
Vol 65 (8) ◽  
pp. 3298-3303 ◽  
Author(s):  
Alexander M. Blinkovsky ◽  
Tony Byun ◽  
Kimberly M. Brown ◽  
Elizabeth J. Golightly

ABSTRACT A novel serine carboxypeptidase (EC 3.4.16.1 ) was found in anAspergillus oryzae fermentation broth and was purified to homogeneity. This enzyme has a molecular weight of ca. 67,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its specific activity is 21 U/mg for carbobenzoxy (Z)-Ala-Glu at pH 4.5 and 25°C. It has a ratio of bimolecular constants for Z-Ala-Lys and Z-Ala-Phe of 3.75. Optimal enzyme activity occurs at pH 4 to 4.5 and 58 to 60°C for Z-Ala-Ile. The N terminus of this carboxypeptidase is blocked. Internal fragments, obtained by cyanogen bromide digestion, were sequenced. PCR primers were then made based on the peptide sequence information, and the full-length gene sequence was obtained. An expression vector that contained the recombinant carboxypeptidase gene was used to transform aFusarium venenatum host strain. The transformed strain ofF. venenatum expressed an active recombinant carboxypeptidase. In F. venenatum, the recombinant carboxypeptidase produced two bands which had molecular weights greater than the molecular weight of the native carboxypeptidase from A. oryzae. Although the molecular weights of the native and recombinant enzymes differ, these enzymes have very similar kinetic parameters.


1975 ◽  
Vol 53 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Graham Moore ◽  
Anita Letter ◽  
Maria Tesanovic ◽  
Karl Lederis

The molecular weights of two active principles extracted from the urophysis of the teleost fish Catostomus commersoni in 0.1 N HCl or in 0.25% acetic acid have been investigated by gel filtration chromatography and SDS–polyacrylamide gel electrophoresis. Two peptides with urotensin I (long-acting rat hypotensive) activity and two peptides with urotensin II (fish smooth muscle stimulating) activity were found by these procedures. The smaller of the two urotensin I peptides (molecular weight 1200–1700), designated urotensin IS, was shown to be a fragment of the larger peptide (molecular weight 2300–3000) which is produced by acid hydrolysis without loss of rat hypotensive activity. The two urotensin II peptides are suggested to represent either a monomer and a dimer or open and closed forms of a peptide.


1987 ◽  
Vol 67 (4) ◽  
pp. 945-952 ◽  
Author(s):  
B. A. MARCHYLO

Sodium dodecyl sulphate gradient polyacrylamide gel electrophoresis (SDSGPAGE) was used to resolve gliadin and high- and low-molecular-weight glutenin subunits from 19 registered Canadian spring wheat cultivars eligible for Canada Western Red Spring (CWRS) and Canada Prairie Spring (CPS) wheat grades and eight nonregistered spring wheat cultivars from the U.S.A. Reproducible molecular weight estimates were obtained for wheat proteins of apparent molecular weights ranging from 34 238 to 136 174 (avg. CV = 0.72%). Eight different patterns of HMW glutenin subunits consisting of 7–11 protein bands were observed for the 27 cultivars and their biotypes. SDSGPAGE was able to discriminate among the majority of cultivars with all non-registered cultivars and their biotypes distinguishable from registered cultivars. Separation of glutenin subunits along with gliadins provided additional protein bands which assisted in the discrimination of cultivars.Key words: SDS gradient PAGE, wheat cultivar identification, gliadin, glutenin subunits


1972 ◽  
Vol 50 (7) ◽  
pp. 775-781 ◽  
Author(s):  
W. L. Lockhart ◽  
W. P. Chung ◽  
David B. Smith

Porcine haptoglobin was tested for reversible dissociation in dilute solution by gel filtration. Elution volume in Bio-Gel P-150 was independent of concentration and shapes of elution profiles failed to show dissociation. Molecular weight in dilute solution was estimated as 96 500. Interchain disulfide bridges were assayed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Partially reduced samples showed a series of intermediates but fully reduced samples showed only heavy and light chains. Intermediates were tentatively identified as to chain composition from their electrophoretic mobilities.


1974 ◽  
Vol 141 (2) ◽  
pp. 413-418 ◽  
Author(s):  
David J. Wright ◽  
Donald Boulter

Zonal isoelectric precipitation was shown to be an effective method for the preparation of legumin which was homogeneous as judged by ultracentrifugation and polyacrylamide-gel electrophoresis. The subunit structure of legumin was investigated by preparative sodium dodecyl sulphate–polyacrylamide-gel electrophoresis and ion-exchange chromatography in urea. Five distinct subunits, of which two were acidic (α) and had a molecular weight of 37000, and three were basic (β) with molecular weights of 20100, 20900 and 23800, were identified. The α and β subunits were present in equimolar amounts in the legumin molecule and, in view of this and molecular-weight considerations, an α6β6 subunit model was proposed for legumin.


1979 ◽  
Vol 57 (19) ◽  
pp. 2044-2049 ◽  
Author(s):  
Brendan T. O'Kennedy ◽  
Charles C. Reilly ◽  
John S. Titus ◽  
Walter E. Splittstoesser

The percentage of globulin from cotyledons of dormant seeds of eight species of the Cucurbitaceae family was similar. After 4 days of germination, the globulin fraction decreased with a concomitant increase in the water-soluble protein fraction. Small changes in total protein occurred. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis showed that the globulins of the eight species were composed of high molecular weight proteins which were different. The subunit arrangement of the globulin suggests a tetramer structure with a molecular weight greater than 200 000. After4 days of germination, a heat-stable, water-soluble protein was produced from the globulin. When this protein was reduced with β-mercaptoethanol, followed by electrophoresis, two peptides with molecular weights of 18 500 and 20 000 were produced in each species. It was concluded that all of the globulins have the same basic structure in different subunit arrangements.


Blood ◽  
1980 ◽  
Vol 56 (4) ◽  
pp. 717-727
Author(s):  
JF DiPersio ◽  
JK Brennan ◽  
MA Lichtman ◽  
CN Abboud ◽  
FH Kirkpatrick

GCT, a human monocyte-like cell line, has been shown to release biochemically distinct colony-stimulating activities (CSAs) for mouse and human marrows. These appear to be periodate-sensitive proteins with critical disulfide bonds. One, of molecular weight 145,000 daltons, stimulates macrophagic colony growth and is related to a 30,000-dalton molecule that also stimulates mouse growth. A 30,000-dalton CSA for human marrow can be separated from the 30,000-dalton mouse CSA by isoelectric focusing and gradient polyacrylamide gel electrophoresis. This distinction agrees with our previous finding of differential neutralization with anti-human urinary CSF antibody. The 30,000-dalton CSAs stimulate neutrophil, neutrophil-monocyte, and eosinophil colony growth in human marrow but only neutrophil and neutrophil-monocyte colonies in the mouse. Subcellular fractionation of GCT cells indicates that there are pools of preformed CSAs primarily associated with the cell cytosol that have similar apparent molecular weights to their secreted counterparts.


1986 ◽  
Vol 250 (3) ◽  
pp. C460-C467 ◽  
Author(s):  
R. J. King ◽  
H. M. Martin ◽  
J. B. Baseman ◽  
J. Morrison-Plummer

We have used monoclonal antibodies developed against the apolipoproteins associated with pulmonary surfactant purified from rabbit lavage fluid to study the expression of epitopes common to these proteins. The pulmonary surfactant contained nearly 20 proteins, of which at least 10 were not derived from serum. Electrophoresis, with sulfhydryl reduction of these proteins indicated apparent molecular weights of approximately 155, 135, 125, and 115 X 10(3) (high-molecular-weight group); 80, 70, and 60 X 10(3) (intermediate group); and 18 through 10 X 10(3) (low-molecular-weight group). Two-dimensional polyacrylamide gel electrophoresis, in which the proteins were electrophoresed without reduction in the first dimension, but with sulfhydryl reduction in the second dimension, revealed that the 80, 70, and 60 X 10(3) proteins dissociated into proteins of nominal molecular weights of 40, 35, and 30 X 10(3), respectively. In contrast, the 125 and 115 X 10(3) proteins of the high-molecular-weight group contained a protein which could only be reduced to a minimum molecular weight of 55 to 60 X 10(3). Monoclonal antibodies generally were of three types: those that reacted strongly with the high-molecular-weight group and weakly with the intermediate group; those that reacted conversely; and those that reacted only with the low-molecular-weight group. Our results indicate that at least two different surfactant apolipoproteins, with differing minimum molecular weights in SDS-polyacrylamide gel electrophoresis, have common epitopes. Although these results cannot certify a physiological relationship between these proteins, they suggest that the intracellular synthesis or extracellular processing of surfactant apolipoproteins may be more complicated than predicted by the findings of previous experiments, perhaps involving the posttranslational assembly of one surfactant protein into oligomers which resist dissociation under the conditions used for the analyses.


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