A cellulase complex in culture filtrates of Penicillium citrinum

1976 ◽  
Vol 22 (8) ◽  
pp. 1153-1159 ◽  
Author(s):  
P. O. Olutiola

During growth in a liquid medium that contained a single soluble or an insoluble cellulosic carbon source Penicillium citrinum released a complex of cellulase enzymes into the medium. A temperature of 30 °C was best for cellulase production. Presence of carbon-containing compounds, particularly glucose, inhibited cellulase activity. The enzyme complex was separated by gel filtration followed by ion-exchange chromatography into 11 components, 4 of high molecular weight and 7 of low molecular weight. One of the components (Bb) had the character of C1 cellulase enzyme. When the components were combined they released more reducing sugars from cullulosic substrates than when they were used singly.

1984 ◽  
Vol 62 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Show-Jy Lau ◽  
Bibudhendra Sarkar

The binding of six trace metals, Mn(II), Ni(II), Zn(II), Cu(II), Cd(II) and Fe(III), to human cord serum has been studied by Sephadex G-100 gel filtration at physiological pH, using radioisotopes as tracers. The results are compared with those obtained from adult serum. In both cord and adult sera, extensive amounts of the metals are bound to high molecular weight proteins. Among them, Fe(III) is mostly bound to transferrin; Ni(II), Zn(II), Cu(II), and Cd(II) are bound to albumin and other macro-molecules. The binding of Mn(II) either to transferrin or albumin is not resolved. Small fractions of Zn(II), Cu(II), and Cd(II) and large fractions of Mn(II) and Ni(II) are found to be associated with low molecular weight components of both sera. The distribution varies from metal to metal. However, the low molecular weight component of the size 1500 – 10 000 is present in all the metals studied. Further purification of this component was attempted by DEAE-cellulose ion-exchange chromatography. The possible identity as well as the biological role played by this particular component of serum in the transport of metals in blood and across membranes is discussed.


1972 ◽  
Vol 130 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Colin H. Self ◽  
P. David J. Weitzman

Two isoenzymes of NADP-linked isocitrate dehydrogenase have been identified in Acinetobacter lwoffi and have been termed isoenzyme-I and isoenzyme-II. The isoenzymes may be separated by ion-exchange chromatography on DEAE-cellulose, by gel filtration on Sephadex G-200, or by zonal ultracentrifugation in a sucrose gradient. Low concentrations of glyoxylate or pyruvate effect considerable stimulation of the activity of isoenzyme-II. The isoenzymes also differ in pH-dependence of activity, kinetic parameters, stability to heat or urea and molecular size. Whereas isoenzyme-I resembles the NADP-linked isocitrate dehydrogenases from other organisms in having a molecular weight under 100000, isoenzyme-II is a much larger enzyme (molecular weight around 300000) resembling the NAD-linked isocitrate dehydrogenases of higher organisms.


1973 ◽  
Vol 58 (3) ◽  
pp. 405-419 ◽  
Author(s):  
M. JOAN REED ◽  
S. R. STITCH

SUMMARY The uptake of 65Zn and [1,2-3H]testosterone by minced tissue of human benign hypertrophic prostates and the subcellular distribution of radioactivity were examined. The nature of steroid and 65Zn binding by the cytosol (105000 g supernatant) fraction was investigated by gel filtration, ion-exchange chromatography and electrophoresis. It was found that steroid binding after incubation at 4°C was specific. One or two regions of steroid binding were observed after gel filtration of the cytosol using Sephadex G-200, depending upon incubation conditions. Binding of 65Zn was found in the low molecular weight peak after G-200 gel filtration. Equimolar CdCl2 and 65ZnCl2 were incubated with [1,2-3H]testosterone and minced tissue and the cytosol was subjected to gel filtration. Compared with control values, without CdCl2, reduction of 65Zn binding by about 50% occurred, while binding of 3H-labelled steroid was unaffected. Electrophoresis and ion-exchange chromatography showed that 65Zn and 3H-labelled steroid were bound to different proteins. A sample of the zinc-binding protein was prepared by ion-exchange chromatography and the homogeneity was checked by electrophoresis.


1981 ◽  
Author(s):  
H R Lijnen ◽  
B Wiman ◽  
B Van Hoef ◽  
D Collen

α2-Antiplasmin (α2AP), the main physiological inhibitor of plasmin in human plasma, is a single–chain glycoprotein with a molecular weight of 67,000 consisting of about 510 amino acids and containing 13 percent carbohydrate.A tryptic digest on 400 mg of reduced, carboxymethylated and citraconylated purified α2AP was performed. Peptides were separated by combinations of ion exchange chromatography, gel filtration and high performance liquid chromatography, and sequenced using the manual Edman degradation. Some peptides were further digested in order to establish overlaps. At the time of submission of this abstract we have sequenced 7 out of the approximately 21 arginyl peptides completely (each between 3 and 21 residues) and are working on the others. At present we have about 200 residues of sequence. Here we only report the stretches of 10 amino acids or more, which may be useful to compare the structure of α2AP with that of other serine protease inhibitors.


Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 113-118 ◽  
Author(s):  
C. Carmona ◽  
S. McGonigle ◽  
A. J. Dowd ◽  
A. M. Smith ◽  
S. Coughlan ◽  
...  

SUMMARYA dipeptidylpeptidase (DPP) was isolated from Fasciola hepatica by gel-filtration and ion-exchange chromatography. The exoproteinase is secreted by newly excysted juveniles, immature and mature flukes. The liver fluke DPP is a serine proteinase of molecular weight > 200 kDa and differs from previously characterized mammalian DPPs in its substrate preference and susceptibility to inactivation by inhibitors. The parasite DPP may function in the latter stages of the proteolytic digestion of host macromolecules. In this manner, the enzyme may be important in providing the parasite with dipeptides that could be absorbed through the intestine as nutrient.


1976 ◽  
Vol 35 (03) ◽  
pp. 576-585 ◽  
Author(s):  
Katalin Váradi ◽  
Susan Elödi

SummaryHuman factor IXa was purified 5,000-fold from serum by ion exchange chromatography. The preparation was free from other clotting factors. Both pH sensitivity and heat stability of purified factor IXa appeared to be different from those of factor IX in the plasma. The molecular weight of human factor IXa is 80,000 as estimated from gel-filtration experiments. Modification of seryl or histidyl side chains abolished the activity of factor IXa.


1996 ◽  
Vol 51 (5-6) ◽  
pp. 429-431 ◽  
Author(s):  
M.O. Ilori ◽  
O.O. Amund ◽  
O. Omidiji

Abstract A proteolytic enzyme produced by a cassava-ferment­ing strain of Micrococcus luteus was extracted and puri­fied 50-fold by gel filtration and ion exchange chromatography. The optimum pH for the enzyme was 7.0, the optimum temperature 25 °C, the apparent molecular weight 42 kDa and the Km value, 0.45 mg ml-1 with casein as substrate. The enzyme was stimulated by Ca2+ and Mg2+ but inhibited by Zn2+ and Co2+ ions. Other inhibitors were EDTA, KCN, citric acid and L-cysteine indicating the enzyme to be a metalloprotease.


1971 ◽  
Vol 121 (3) ◽  
pp. 353-362 ◽  
Author(s):  
T. M. Wood

1. Cell-free culture filtrates of the fungus Fusarium solani were examined for homogeneity with respect to β-d-glucosidase and Cx activities. 2. o-Nitrophenyl β-d-glucoside and cellobiose were both used as substrates for β-d-glucosidase activity. 3. No evidence for the non-identity of nitrophenyl β-d-glucosidase and cellobiase activities could be found, either by heat treatment, gel filtration on Sephadex G-100 or by isoelectric focusing. 4. The β-d-glucosidase component was also a feeble exo-β-glucanase: it had a molecular weight of approx. 400000. 5. The fall in viscosity of a solution of CM-cellulose, the formation of reducing sugars in a solution of CM-cellulose and the solubilization of phosphoric acid-swollen cellulose (Walseth cellulose), were all used for the measurement of Cx activity. 6. The ratio of the two types of CM-cellulase activity was not changed after gel filtration on Sephadex G-100 or after chromatography on DEAE-Sephadex. 7. Three peaks of Cx activity were obtained after electrofocusing, but all three possessed the same ratio of the two types of CM-cellulase activity as well as the same CM-cellulase/Walseth activity ratio, as the unfractionated enzyme; all three isoenzymes (isoelectric points, 4.75, 4.80–4.85 and 5.15) acted in synergism with a mixture of the C1 and the β-d-glucosidase components to the same extent in the solubilization of cotton fibre. 8. The molecular weight of the Cx component was approx. 37000.


1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy

The exocellular enzyme β-glucosidase of Candida molischiana was studied. This strain is able to ferment soluble cellodextrins. The enzyme was partially purified by ion-exchange chromatography and gel filtration. The molecular weight of this enzyme was 120 000; its optimum pH was between 4 and 4.5 and its optimum temperature was 60 °C. This enzyme was active against different soluble glucosides and was inhibited by p-chloromercuribenzoate, gluconolactone, and glucose. A "glucosyltransferase" activity appeared in the presence of ethanol. The biosynthesis of the enzyme was constitutive but repressed by glucose.


1978 ◽  
Vol 175 (1) ◽  
pp. 35-46 ◽  
Author(s):  
A J MacGillivray ◽  
C Johnston ◽  
R MacFarlane ◽  
D Rickwood

After labelling of mouse liver nuclei with [gamma-32P]ATP in vitro, 10-20% of the radioactivity incorporated into the saline-soluble nuclear and HAP2 chromatin fractions was located in a low-molecular-weight component (component 10) with pI near 4.5 in urea. By using combinations of ion-exchange chromatography, preparative thin-layer isoelectric focusing and gel filtration, this component was isolated from both nuclear fractions. Recovery from the saline-soluble fraction was poor under conditions that allow endogenous phosphatases to be active. Component 10 was shown to be a phosphoprotein on the basis of enzyme-digestion experiments and the detection of phosphoserine and phosphothreonine. The 32P radioactivity did not appear to be associated with phosphorylated basic amino acids. Its molecular weight was determined by gel chromatography and electrophoresis in sodium dodecyl sulphate/polyacrylamide gels as approx. 10000, and tryptic digestion of the reduced carboxymethylated protein in urea yielded two 32P-labelled peptides. It has not been possible as yet to assign a function to component 10, though its similarity to other low-molecular-weight acidic proteins is discussed.


Sign in / Sign up

Export Citation Format

Share Document