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PubMed1987

Comparison of the properties of the purified beta-glucosidase from the transformed strain of Saccharomyces cerevisiae TYKF2 with that of the donor strain Kluyveromyces fragilis Y610.

Saccharomyces cerevisiae TYKF2 was obtained by cloning in S. cerevisiae the gene coding for beta-glucosidase in Kluyveromyces fragilis Y610 (ATCC 12424). The beta-glucosidases of both organisms were purified and their biochemical characteristics were determined. The two beta-glucosidases had the same enzymatic properties as those previously described in the literature. The strain S. cerevisiae TYKF2 is able to produce enhanced amounts of enzyme.

Chromatography, Gel↗

PubMed1994

[Cloning and expression of beta-glucosidase gene in Xanthomonas campestris XA5-5].

A beta-glucosidase gene from Xanthomonas campestris XA5-5 was cloned in Escherichia coli with the broad-host-range plasmid pRK404. The beta-glucosidase encoding plasmid designated pLZS1 contained a 1.1kb PstI DNA fragment deriving from XA5-5. The plasmid pLZS1 was transconjugated by filter mating into XA5-5 producing homologous clones XA5-5(pLZS1). Plasmid stability analysis revealed that pLZS1 was more stable in XA5-5 than in E. coli JM83. The level of beta-glucosidase expressed in XA5-5 (pLZS1) was much higher than in E. coli JM83 (pLZS1) using salicin as the substrate. From the results obtained, it seems that the gene product of this cloned DNA fragment has higher affinity to salicin substrate, and in some sense reduces the affinity between the enzyme and pNPG substrate in XA5-5.

Cloning, Molecular↗

PubMed1993

Properties of almond beta-glucosidase immobilized on concanavalin A-sepharose.

Lyophylized almond beta-glucosidase (EC 3.2.1.21) has been adsorbed onto Concanavalin A-Sepharose (CAS). The yield of the enzymatic units of the CAS-enzyme complex preparation was 131%. The values of the kinetic parameters of the free beta-glucosidase were: kM = 1.7 mM and Vmax = 330.1 U/mg protein. The immobilised form showed the following values: kM = 1.7 mM and Vmax = 402.6 U/mg protein. Both enzymatic forms showed essentially the same temperature- and pH-activity patterns (temperature optimum: 50 degrees C and pH optimum approx. 6.0), however, the pH stability of the CAS-enzyme complex at pH 6 was significantly higher than the beta-glucosidase in free solution.

Enzymes, Immobilized↗

PubMed1977

[Substrate specificity of sweet almond beta-glucosidase].

Beta-Glucosidase, beta-galactosidase, beta-xylosidase and alpha-L-arabinosidase activities of partially purified preparation of almond emulsin were investigated using chromatography, electrophoresis in polyacrylamide gel and isoelectric focusing. Beta-Glucosidase was found to exist as two components having equal molecular weight. Aggregation of the components with inactive proteins probably results in the appearance of multiple native forms which have similar specific activities. In no case separation of the beta-glucosidase activity from the accompanied activities was achieved. It is concluded therefore that these activities are exhibited by an enzyme which is not strictly specific to the C4, C6 stereochemistry for hexosides and to that of C4, C5 for pentozides.

Arabinose↗

PubMed1995

Effect of a detergent Triton X-100 on growth and alpha-glucosidase production by the thermophilic fungus Malbranchea sulfurea.

A detergent Triton X-100 was found to affect maltose-induced synthesis of extracellular, mycelial and intracellular alpha-glucosidase in the thermophilic fungus Malbranchea sulfurea. The extracellular fraction of the total alpha-glucosidase yield was found to be 90.7% and 40.4% in the presence and absence of the detergent, respectively. Data suggest that supplementation of the detergent in the medium resulted in the partial solubilization of the cell-bound alpha-glucosidase and caused its release in the growth medium.

Cell Division↗

PubMed1996

Separation and partial purification of beta-glucosidase and two endoglucanases in Aspergillus niveus.

The thermotolerant Aspergillus niveus strain RMF 7883 was grown in Czapek medium, with filter paper cellulose. The proportion of mycelial-bound to extracellular enzymes was studied. Most of the beta-glucosidase (80.9%) and endoglucanases (78.3%) activities were extracellular. The extracellular endoglucanases and beta-glucosidase were separated and partially purified by Sephadex G-100 gel filtration, followed by ion exchange chromatography on CM-trisacryl M. Two extracellular endoglucanases, EG I and EG II (130 kDa and 35 kDa, respectively), and beta-glucosidase (194 kDa) were isolated from culture filtrate.

Aspergillus nidulans↗

PubMed1977

[Specificity of fungal alpha-glucosidases].

Studies of substrate and cosubstrate specificities of mould alpha-glucosidases suggest that the binding site of the active center of mould alpha-glucosidase consits of two subsites--glucone and aglucone ones. The glucone site is capable to bind glucose and mannose, whereas the aglucone one- some compounds whose affinity for the enzyme may be expressed as follows: glucose greater than galactose greater than paranitrophenol greater than or equal to glycerol greater than ethanol approximately equal to methanol. Upon interaction of enzyme with alpha-D-glucoside the formation of a productive enzyme-substrate complex occurs when the glucosyl residue located at the non-reducible end of the substrate molecule occupies the glucone subsite and aglucone of the substrate occupies the aglucone subsite of the enzyme. After removal of the first product from the aglucone subsite the substrate is bound at this subsite. It is assumed that under cosubstrate excess it is capable to bind at the aglucone subsite prior to the removal of the first product and the formation of the substituted form enzyme--glycosyl. Under these conditions the cosubstrate removes the substrate from the aglucone subsite resulting in a formation of a non-productive tertiary complex enzyme--substrate--cosubstrate. The anomeric configuration of glucose produced under the action of alpha-glucosidase on maltose and starch was determined using a kinetic method.

Aspergillus↗

PubMed1997

The effect of different pectic growth substrates on beta-glucosidase in Fusarium oxysporum f. sp. radicis lycopersici: partial purification and characterization.

Fusarium oxysporum f. sp. radicis lycopersici produces beta-glucosidase activities when it grows on pectin and glucose. The pectins were better substrates than glucose. In the medium containing galacturonic acid or sucrose the activity was present in low levels and at the end of autolysis. A beta-glucosidase from the pectin medium was purified by ion exchange chromatography followed by gel filtration. The enzyme was a unique band of protein in SDS-PAGE and isoelectric focussing. It had a molecular weight of 86,000 and a pI of 4.8. This beta-glucosidase was a glycoprotein.

Chromatography, Ion Exchange↗

PubMed1997

Purification and some properties of beta-glucosidase from Aspergillus niger IBT-90.

beta-glucosidase (EC 3.2.1.21) was isolated from the culture filtrate of Aspergillus niger IBT-90. The crude extracellular enzyme preparation was fractionated by six step purification procedure, (NH4)2SO4 precipitation, gel filtration on Bio-Gel P-10 and P-100, an ion-exchange chromatography on DEAE Bio-Gel A, yielding beta-glucosidase with an isoelectric point at pH 4.05. The enzyme was found to be a dimer with an apparent molecular weight of approximately 200 kDa as determined by size exclusion chromatography. It is composed of two apparently identical subunits of about 100 kDa (determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis). A. niger IBT-90 beta-glucosidase contains 33% carbohydrates. It is most active towards cellobiose at pH 4.8 and 65 degrees C. The enzyme sequentially splits off glucose units from non reducing ends of collodextrins. Kinetic studies on cellobiose and salicin hydrolysis, in concentration from 0.1 to 5.0 mM, resulted in non-linear Lineweaver-Burk and Hanes plots, whereas p-nitrophenyl-beta-D-glucopiranoside (pNPG) did not induce this type of effect. No metal ion is required for the enzyme catalytic activity. Hg2+ and N-bromosuccinimide (NBS) are its strong inhibitors. Glucono-delta-lactone and glucose are competitive inhibitors of the enzyme and glucono-delta-lactone is more potent of the two.

Aspergillus niger↗

PubMed1975

[Tumour hyperacidulation through intravenous glucose infusion enhanced by amygdalin and beta-glucosidase application (author's transl)].

Tumour peracidity in otherwise moderately hyperacidulated tumours or tumour regions of DS carcinosarcoma-bearing Wistar rats attained by glucose infusion was substantially increased by simultaneous infusion of amygdalin and intratumoral i.m. or i.v. application of beta-glucosidase. Here the pH value of healthy tissue, measured at the sceletal muscle, remained unchanged. By means of the said process, tumour hyperacidulation has been raised to a level of deltapH =0.97; attaining a pH difference between tumourous and normal tissue of up to deltapH = 1.6. In one case, the slope of pH reduction in the tumour increased to 870%. Moreover, combined administration of glucose, amygdalin and beta-glucosidase evoked a significant cancerostatic effect hypogenesis, tumour regression) being comparable with the action of an Ifosfamid dosage of 150 mg-kg-1. However, i.m. and i.v. application of beta-glucosidase under narcosis results in an overall process that still remains somewhat too toxic. Hence optimizing studies are intended with the particular aim to further improve the comparability of this process.

Acids↗

PubMed2001

Molecular cloning of an alpha-glucosidase-like gene from Penicillium minioluteum and structure prediction of its gene product.

The dexC cDNA, which is expressed in dextran-containing medium by the filamentous fungus Penicillium minioluteum, was cloned and sequence characterized. The cDNA sequence comprises 1859 bp plus a poly (A) tail, coding for a predicted protein of 597 amino acids. The genomic counterpart was isolated by PCR, finding three introns in its sequence. The dexC gene was located by Southern blot in the same 9-kb fragment that the previously isolated dextranase-encoding gene (dexA). Sequence analysis revealed that the deduced DexC protein belongs to glycosyl hydrolase family 13, showing a high sequence identity (58%) with Aspergillus parasiticus alpha-1,6-glucosidase. In addition, the high sequence identity (51%) between DexC protein and oligo-1,6-glucosidase of Bacillus cereus, with three-dimensional (3D) structure determined, leads us to proposed a 3D model for the structural core of DexC protein.

Amino Acid Sequence↗

PubMed1981

Production of beta-glucosidase, exo-beta-1,4-glucanase and endo-beta-1,4-glucanase by selected microscopic fungi.

Production of beta-glucosidase, exo-beta-1,4-glucanase and endo-beta-1,4-glucanase was screened in 58 species of imperfect fungi, mucoral fungi and some ascomycetes. beta-Glucosidase activity was found in all of the tested microorganisms, exo-beta-1,4-glucanase activity in 23, and endo-beta-1,4=glucanase activity in 38 microorganisms. Growth on cellobiose was found in all tested microorganisms, growth on carboxymethylcellulose in in 38 tested strains.

Ascomycota↗

PubMed1982

Vacuolar myopathy with type 2 A fiber atrophy and type 2 B fiber deficiency. A case of childhood form acid alpha-1,4-glucosidase deficiency.

This report describes a female patient with childhood form of acid maltase deficiency who survived till fifteen years old. Although acid alpha-1,4-glucosidase was deficient in the liver, kidney, skeletal and cardiac muscles, neutral alpha-1,4-glucosidase was present in normal concentrations in those organs. On light microscopic examination, numerous intracytoplasmic vacuoles containing acid phosphatase positive granules and PAS positive materials were present in both type 1 and 2 A fibers, predominantly in the latter. The striking finding in the present case was a selective type 2 fiber atrophy with type 2 B fiber deficiency believed to result from type 2 motor neuron dysfunction in the spinal cord. Electron microscopic study revealed extensive glycogen particle accumulation, autophagic vacuoles and myelin figures in the muscle fibers.

Adolescent↗

PubMed1963

Fractionation of beta-glucosidases and related extracellular enzymes from Aspergillus niger.

Industrial concentrates from Aspergillus niger culture filtrates were fractionated by ion-exchange and adsorption chromatography. Several other types of hydrolases were completely removed. Eight partially purified components were obtained. Using specific activity as an estimate of purification, one aryl-beta-glucosidase was purified 35-fold. Another component showed 147-fold purification using a viscosimetric assay with carboxymethylcellulose as substrate. The aryl-beta-glucosidase was distinctly more thermolabile than the carboxymethylcellulase.

Aspergillus↗

PubMed1980

White blood cells and the diagnosis of alpha-glucosidase deficiency.

Leukocytes were obtained from 14 healthy subjects, one patient with the infantile form, two patients with the adult variant of acid maltase deficiency, two patients with chronic myelocytic leukemia, two patients with acute myeloid leukemia, and two patients with chronic lymphotic leukemia. In addition, lymphocytes were prepared from three normal subjects, and five established lymphoid lines were used. Cells were extracted either with Triton 0, 2%, or with water followed by 0.2% Triton. alpha-Glucosidase activity was measured in water homogenates, water extracts after centrifugation, and Triton extracts, with or without antisera directed against acid maltase (EC 3.2.1.3) and renal maltase (EC 3.2.1.20). The percentage of acid and renal maltases was then calculated in each soluble fraction. Normal whole leukocytes (mostly granulocytes) contain both acid and "renal" maltases, whereas normal lymphocytes contain very little or no "renal maltase." This isozyme is present in chronic myelocytic leukemia, but is absent in acute myeloid and chronic lymphocytic leukemia as well as in established lymphoid lines. Acid maltase is almost completely extracted with water, whereas renal maltase is extracted only with Triton. From the results, it appears that for the diagnosis of alpha glucosidase deficiency, cells should be extracted in water and centrifuged before determination. Lymphocytes, which are devoid of renal maltase, are a better diagnostic material than are granulocytes.

Glucan 1,4-alpha-Glucosidase↗

PubMed1988

Receptor-mediated uptake of acid alpha-glucosidase corrects lysosomal glycogen storage in cultured skeletal muscle.

Attempts at treatment of glycogenosis type II and other lysosomal storage disorders by enzyme replacement have been reported. Parenteral enzyme administration has been ineffectual. Treatment by bone marrow transplantation is currently under investigation. We have used cultured skeletal muscle cells from a patient with infantile glycogenosis type II to study fundamental aspects of enzyme replacement therapy. Efficient uptake of acid alpha-glucosidase was achieved by using the mannose-6-phosphate receptor on the cell surface as a target for an enzyme precursor with phosphorylated high-mannose types carbohydrate chains purified from human urine. We found that the enzyme was channeled to the lysosomes and converted to mature acid alpha-glucosidase. Glycogen storage was reversed. The results are discussed in relation to treatment of glycogenosis type II.

Carrier Proteins↗

PubMed1999

The degradation of glycogen in the lysosomes of newborn rat hepatocytes: glycogen-, maltose- and isomaltose-hydrolyzing acid alpha glucosidase activities in liver.

The lysosomal glucosidase activities and glycogen degradation in newborn rat liver were studied by using biochemical assays, electron microscopy and quantitative morphometry. Glycogen-hydrolyzing, maltose-hydrolyzing and isomaltose-hydrolyzing activities were low at birth but increased afterwards. At the age of 6 hours they were markedly elevated. Actinomycin prevented the development of glucosidase activities indicating that these depend on protein synthesis. Parenteral glucose inhibited all three activities. This was apparently due to the abolition of normal postnatal hypoglycemia and the need for blood glucose. Cyclic AMP increased the glycogen-hydrolyzing but not the maltose-hydrolyzing activity. Propranolol inhibited the glycogen-hydrolyzing but not the maltose-hydrolyzing activity. The observations of this study provide further support for the hypothesis made by previous investigators that these activities are due to different enzymes.

Animals↗

PubMed1999

Comparative study of the inhibition of alpha-glucosidase, alpha-amylase, and cyclomaltodextrin glucanosyltransferase by acarbose, isoacarbose, and acarviosine-glucose.

Bacillus stearothermophilus maltogenic amylase hydrolyzes the first glycosidic linkage of acarbose to give acarviosine-glucose. In the presence of carbohydrate acceptors, acarviosine-glucose is primarily transferred to the C-6 position of the acceptor. When d-glucose is the acceptor, isoacarbose is formed. Acarbose, acarviosine-glucose, and isoacarbose were compared as inhibitors of alpha-glucosidase, alpha-amylase, and cyclomaltodextrin glucanosyltransferase. The three inhibitors were found to be competitive inhibitors for alpha-glucosidase and mixed noncompetitive inhibitors for alpha-amylase and cyclomaltodextrin glucanosyltransferase. The K(i) values were dependent on the type of enzyme and their source. Acarviosine-glucose was a potent inhibitor for baker's yeast alpha-glucosidase, inhibiting 430 times more than acarbose, and was an excellent inhibitor for cyclomaltodextrin glucanosyltransferase, inhibiting 6 times more than acarbose. Isoacarbose was the most effective inhibitor of alpha-amylase and cyclomaltodextrin glucanosyltransferase, inhibiting 15.2 and 2.0 times more than acarbose, respectively.

Acarbose↗