Purification and some properties of β-glucosidase from the ectomycorrhizal fungus Pisolithus tinctorius strain SMF

1993 ◽  
Vol 39 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Weiguo Cao ◽  
Don L. Crawford

A cell-associated β-glucosidase was purified 152-fold to homogeneity from the ectomycorrhizal fungus Pisolithus tinctorius strain SMF. The apparent molecular weight of the native protein, as determined by size exclusion chromatography, was approximately 450 000. A single band with a molecular weight of 150 000 was obtained after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). Thus, the native enzyme may consist of three monomers. The pI of the enzyme was determined to be 3.8 by isoelectric focusing. The enzyme had an optimal pH of 4.0 and an optimal temperature for activity of 65 °C. It showed a high substrate specificity toward aryl-β-glucosides, such as p-nitrophenyl β-D-glucopyranoside (PNPG), and β-1,6 glucosidic linkages. Cellobiose was hydrolyzed at about two-thirds the rate of PNPG. The Km for hydrolysis of PNPG was 0.87 mM. Strong inhibitors of the enzyme were aluminum, copper, ethylenediaminetetraacetic acid (EDTA), deoxynojirimycin, gluconic acid, and SDS. Calcium, manganese, and p-hydroxymercuribenzoic acid reduced the activity to a lesser extent. Potassium, mercury, cobalt, dithiothreitol, and glucosamine had no effect on activity. Enzyme activity was slightly increased to 112% in the presence of 1% glycerol. The enzyme was more stable under acidic conditions than under alkaline conditions.Key words: Pisolithus, ectomycorrhizal, β-glucosidase, purification.


1993 ◽  
Vol 71 (1-2) ◽  
pp. 85-89 ◽  
Author(s):  
Jean Labrecque ◽  
Pangala V. Bhat ◽  
André Lacroix

A NAD-dependent aldehyde dehydrogenase (EC 1.2.1.3) which catalyzes the oxidation of retinal to retinoic acid was purified to homogeneity from rat kidney by using Affi-Gel blue affinity chromatography and chromatofocusing, followed by Mono-Q anion-exchange chromatography. The apparent molecular weight of the native enzyme determined by size-exclusion fast protein liquid chromatography was 140 000. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis gave a subunit molecular weight of 53 000. The isoelectric point as measured by chromatofocusing was 8.5. The enzyme also catalyzed the oxidation of acetaldehyde, but showed much lower Km value for the retinal substrate. We suggest that aldehyde dehydrogenase found in the kidney may be a specific retinal dehydrogenase, involved in vitamin A metabolism.Key words: aldehyde dehydrogenase, vitamin A, retinal, retinoic acid, kidney.



1989 ◽  
Vol 40 (3) ◽  
pp. 675 ◽  
Author(s):  
DJ Tucker ◽  
AHF Hudson ◽  
A Laudani ◽  
RC Marshall ◽  
DE Rivett

The proteins from a range of cashmere, mohair, angoratcashmere crossbred and wool fibre samples were extracted at pH 8 with 8 M urea containing dithiothreitol, and were then radiolabelled by S-carboxymethylation using iodo(2-14C) acetate. The proteins from each sample were examined by two dimensional polyacrylamide gel electrophoresis in which the separation in the first dimension was according to charge at pH 8.9 and in the second dimension according to apparent molecular weight in the presence of sodium dodecyl sulfate. After electrophoresis the proteins were detected by fluorography. Protein differences in keratin samples from some individual goats existed, although the overall protein patterns were similar. None of the differences were consistent with any one goat fibre type. The protein patterns obtained for fibre samples from individual cashmere goats showed some differences when compared to those found for commercial blends from the same country of origin, indicating that blending can mask any animal-to-animal variation. While the electrophoretic technique does not unequivocally distinguish between cashmere, mohair and angora/cashmere crossbred fibres it does differentiate between wool and goat fibres.



Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 472
Author(s):  
Richard Marchal ◽  
Thomas Salmon ◽  
Ramon Gonzalez ◽  
Belinda Kemp ◽  
Céline Vrigneau ◽  
...  

Botrytis cinerea is a fungal pathogen responsible for the decrease in foamability of sparkling wines. The proteolysis of must proteins originating from botrytized grapes is well known, but far less information is available concerning the effect of grape juice contamination by Botrytis. The impact from Botrytis on the biochemical and physico-chemical characteristics of proteins released from Saccharomyces during alcoholic fermentation remains elusive. To address this lack of knowledge, a model grape juice was inoculated with three enological yeasts with or without the Botrytis culture supernatant. Size exclusion chromatography coupled to multi-angle light scattering (SEC-MALLS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) techniques (AgNO3 and periodic acid Schiff staining) was used in the study. When Botrytis enzymes were present, a significant degradation of the higher and medium MW molecules released by Saccharomyces was observed during alcoholic fermentation whilst the lower MW fraction increased. For the three yeast strains studied, the results clearly showed a strong decrease in the wine foamability when synthetic musts were inoculated with 5% (v/v) of Botrytis culture due to fungus proteases.



2000 ◽  
Vol 66 (4) ◽  
pp. 1379-1384 ◽  
Author(s):  
Katrien M. J. Van Laere ◽  
Tjakko Abee ◽  
Henk A. Schols ◽  
Gerrit Beldman ◽  
Alphons G. J. Voragen

ABSTRACT This paper reports on the effects of both reducing and nonreducing transgalactooligosaccharides (TOS) comprising 2 to 8 residues on the growth of Bifidobacterium adolescentis DSM 20083 and on the production of a novel β-galactosidase (β-Gal II). In cells grown on TOS, in addition to the lactose-degrading β-Gal (β-Gal I), another β-Gal (β-Gal II) was detected and it showed activity towards TOS but not towards lactose. β-Gal II activity was at least 20-fold higher when cells were grown on TOS than when cells were grown on galactose, glucose, and lactose. Subsequently, the enzyme was purified from the cell extract of TOS-grown B. adolescentis by anion-exchange chromatography, adsorption chromatography, and size-exclusion chromatography. β-Gal II has apparent molecular masses of 350 and 89 kDa as judged by size-exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively, indicating that the enzyme is active in vivo as a tetramer. β-Gal II had an optimal activity at pH 6 and was not active below pH 5. Its optimum temperature was 35°C. The enzyme showed highestV max values towards galactooligosaccharides with a low degree of polymerization. This result is in agreement with the observation that during fermentation of TOS, the di- and trisaccharides were fermented first. β-Gal II was active towards β-galactosyl residues that were 1→4, 1→6, 1→3, and 1↔1 linked, signifying its role in the metabolism of galactooligosaccharides by B. adolescentis.



1984 ◽  
Vol 160 (3) ◽  
pp. 772-787 ◽  
Author(s):  
J A Schmidt

A protocol for the rapid, efficient purification of the major charged species of human interleukin 1 (IL-1) has been developed using high performance anion exchange and size exclusion chromatography. The isolated material is pure as determined by sodium dodecyl sulfate (SDS) gradient polyacrylamide gel electrophoresis (PAGE) and analytical isoelectric focusing (IEF). The molecular weight of the purified material is 15,000 and the isoelectric point (pI) is 6.8, values that are in good agreement with those previously reported for human IL-1. 10(-10) M concentrations of the purified material give half-maximal stimulation in the thymocyte proliferation assay. Amounts of IL-1 sufficient for receptor studies and detailed biochemical analysis can now be produced on a regular basis.



1975 ◽  
Vol 30 (9-10) ◽  
pp. 615-621 ◽  
Author(s):  
Hans Craubner ◽  
Friederike Koenig ◽  
Georg H. Schmid

The molecular weight and hydrodynamic properties of a polypeptide isolated from the lamellar system of Antirrhinum chloroplasts were determined in sodium dodecyl sulphate solution by measurement of sedimentation velocity, diffusion and effective partial specific volume. The polypeptide fraction exhibits a molecular weight of 25 000 which agrees with the apparent molecular weight found by polyacrylamide gel electrophoresis. The molecular weight of the polypeptidesodium dodecyl sulphate micelle was 54 000, with a friction ratio of 1.6 which indicates an effective asymmetric hydrodynamic shape. For binding measurements self-diffusion equilibrium dialysis with dodecyl [35S] sulphate was used. In this case, dialysis equilibrium was reached within about 10 hours, in contrast to the dialysis with initial concentration differences which requires much longer times. A binding value of δD = 1.15g sodium dodecyl sulphate per g polypeptide was obtained which corresponds to a molar binding ratio of 100 mol dodecyl sulphate bound per mol of polypeptide. After the removal of dodecyl sulphate the polypeptide is present in an aggregated state. In phosphate buffers of pH 6.8 and 7.5 the aggregates preponderantly have sedimentation coefficients of 11.7 and 6.8 Svedberg units respectively. Assuming equivalent spheres the molecular weights were calculated to be 340 000 and 150 000.



1975 ◽  
Vol 151 (3) ◽  
pp. 685-697 ◽  
Author(s):  
M Letarte-Muirhead ◽  
A N Barclay ◽  
A F Williams

The Thy-1-molecule, which was identified by its antigenic activities, has been purified from rat thymocytes. The purification involved preparation of crude membranes and solubilization in deoxycholate, followed by gel filtration and affinity chromatography on antibody or lectin columns. In all cases the purified molecule was a glycoprotein that did not form higher polymers and was not associated with other polypeptide chains. The Thy-1 glycoprotein could be found in two forms, one binding to lentil lectin, the other not. Both forms had the same detectable antigens and were of a similar but not identical size. After sodium dodecyl sulphate-polyacrylamide-gel electrophoresis the apparent molecular weight of Thy-1 binding to lentil lectin was 25 000, whereas that not binding to the lectin was 27 000, with heterogeneity towards forms of apparently higher molecular weight.



2021 ◽  
Vol 22 (15) ◽  
pp. 7777
Author(s):  
Lydia K. Muranova ◽  
Vladislav M. Shatov ◽  
Andrey V. Slushchev ◽  
Nikolai B. Gusev

In this study, a reliable and simple method of untagged recombinant human HspB7 preparation was developed. Recombinant HspB7 is presented in two oligomeric forms with an apparent molecular weight of 36 kDa (probably dimers) and oligomers with an apparent molecular weight of more than 600 kDa. By using hydrophobic and size-exclusion chromatography, we succeeded in preparation of HspB7 dimers. Mild oxidation promoted the formation of large oligomers, whereas the modification of Cys 126 by iodoacetamide prevented it. The deletion of the first 13 residues or deletion of the polySer motif (residues 17–29) also prevented the formation of large oligomers of HspB7. Cys-mutants of HspB6 and HspB8 containing a single-Cys residue in the central part of the β7 strand in a position homologous to that of Cys137 in HspB1 can be crosslinked to the wild-type HspB7 through a disulfide bond. Immobilized on monoclonal antibodies, the wild-type HspB6 interacted with the wild-type HspB7. We suppose that formation of heterodimers of HspB7 with HspB6 and HspB8 may be important for the functional activity of these small heat shock proteins.



Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 52-59
Author(s):  
GE Davies ◽  
CM Cohen

Human platelets were tested for the presence of proteins immunologically cross-reactive with red cell spectrin and protein 4.1. As assessed by indirect immunofluorescence microscopy, platelets were specifically reactive with affinity-purified rabbit antisera against red cell spectrin and protein 4.1. The immunoreactive platelet constituents were further analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis, followed by electrophoretic transfer to nitrocellulose paper and immunoperoxidase staining. We found that whole platelets, membranes, and cytoskeletal preparations isolated by Triton X-100 extraction contain small amounts of proteins reacting with anti-spectrin or anti-protein 4.1 antiserum. The immunoreactive spectrin-like platelet protein has an apparent molecular weight of 240,000 and comigrates with the alpha-subunit of red cell spectrin. The major immunoreactive protein 4.1-like constituent has an apparent molecular weight of 78,000, which is slightly less than that of red cell protein 4.1. We conclude that platelets contain a spectrin- like protein which, by analogy with red cell spectrin, may have a role in membrane-cytoskeletal attachment. The properties and function of the platelet protein 4.1-like constituent are not yet known.



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