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PubMed1994

Herbivore-induced volatiles: the emission of acyclic homoterpenes from leaves of Phaseolus lunatus and Zea mays can be triggered by a beta-glucosidase and jasmonic acid.

The treatment of healthy, undamaged plants of the Lima bean Phaseolus lunatus with solutions of a beta-glucosidase from bitter almonds (at 5 U.ml-1) through the petiole results in an enhanced emission of volatiles to the environment. The compounds are identical with those emitted in response to infestation with the red spotted spider mite Tetranychus urticae. Dominant products are the two acyclic homoterpenes 4,8-dimethyl-1,3E,7- dimethylnonatriene (homoterpene I) and 4,8,12-trimethyl-1,3E,7E,11-tridecatetraene (homoterpene II) which are of sesquiterpenoid and diterpenoid origin. Therefore, a beta-glucosidase of the herbivore may be considered as the true elicitor for the odor induction. Homoterpene I and most other of the herbivore-induced volatiles can also be triggered by treatment of the plant with solutions of jasmonic acid (JA) at 100 nmol.ml-1 to 10 mumol.ml-1. The C16 homoterpene II is not significantly induced by JA. The time-course of the enzymatic- and the JA-triggered induction of the volatiles is identical. The dose-response to JA parallels previous reports on alkaloid induction in cell cultures. In corn plants (Zea mays) JA triggers the emission of all volatiles which are known to be emitted in response to the damage by the beet army worm Spodoptora exigua. In summary, the emission of volatiles after damage by a herbivore resembles the production of phytoalexins in response to an attacking microorganism and uses similar elicitors and internal transduction pathways.

Animals↗
PubMed1993

Evaluation on the hydrolysis of methylumbelliferyl-tetra-N-acetylchitotetraoside by various glucosidases. A comparative study.

1. In human plasma, an enzyme is present which hydrolyzes 4-methylumbelliferyl-tetra-N-acetylchitotetraoside. The function of this enzyme is unknown. 2. We have examined whether hyaluronidase, neutral endoglucosaminidase, N-acetyl-beta-D-hexosaminidase, aspartylglucosaminidase, beta-D-glucosidase, and chitobiase could hydrolyze MU-TACT. The results obtained are detailed below. 3. A purified commercial preparation of hyaluronidase does not hydrolyze MU-TACT. 4. Substrate specificity requirements, pH optimum and subcellular localization indicate that neutral endoglucosaminidase is distinguishable from MU-TACT hydrolase. Also commercial neutral endoglucosaminidase D and H have no affinity towards MU-TACT. 5. N-Acetyl-beta-D-hexosaminidase is different from MU-TACT hydrolase for the following reasons: (a) a purified enzyme preparation does not hydrolyze MU-TACT; (b) there is no correlation in the activity of the enzymes; (c) MU-TACT hydrolase is not deficient in cells of a patient with a deficiency of total N-acetyl-beta-D-glucosaminidase; and (d) the 2 enzymes have very different chromatographic characteristics and Con A binding properties. 6. Enzyme characteristics, substrate structural requirements and a lack of correlation with MU-TACT hydrolase activity suggest that aspartylglucosaminidase, beta-D-glucosidase, and chitobiase are not involved in the hydrolysis of MU-TACT. 7. None of the enzymes which we have considered corresponds to MU-TACT hydrolase. The exact nature and the function of the enzyme remains an enigma.

Animals↗
PubMed1992

Isolation and characterization of alpha-glucosidase from Aspergillus niger.

alpha-Glucosidase is an enzyme widely used in biochemical analytical methods. Aspergillus niger was selected as a potential source for its production. Conditions for glucosidase production were optimized and the enzyme was isolated from the culture supernatant by dialysis and anion-exchange chromatography. The activity of the enzyme was determined by maltose hydrolysis to glucose, which was determined using a glucose-specific electrode or by high-performance liquid chromatography. The isolated enzyme was further characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, substrate specificity and fast protein liquid chromatography. The Michaelis constant, optimal temperature and stability of the enzyme preparation were determined.

Anions↗
PubMed1994

Purification of an acidic coniferin-hydrolysing beta-glucosidase from developing xylem of Pinus banksiana.

Two cytosolic, acidic (pI 3.8) glycoproteins (M(r) 110,000 and 90,000) from lignifying xylem of Pinus banksiana were electrophoretically isolated and confirmed by combined gas chromatography-mass spectrometry to be capable of hydrolysing E-coniferin to trans-coniferyl alcohol. These isoenzymes yielded identical N-terminal sequences having negligible homology with documented glucosidases, suggesting that they constitute a novel form of beta-glucosidase.

Amino Acid Sequence↗
PubMed1991

Hydrolytic reactions in two-phase systems. Effect of water-immiscible organic solvents on stability and activity of acid phosphatase, beta-glucosidase, and beta-fructofuranosidase.

The stability and activity of three hydrolytic enzymes, acid phosphatase (EC 3.1.3.2), beta-fructofuranosidase (EC 3.2.1.26), and beta-glucosidase (EC 3.2.1.4), were studied at 30 degrees C in two-phase systems. They were prepared with equal quantities of buffered water and a water-immiscible organic solvent. Low-molecular-weight acetates and paraffins were tested in this investigation. The kinetic constant of storage inactivation was correlated with the logarithm of solvent polarity. Enzyme stability in the presence of organic phases, whose log P value was included in 1.2-2.2, was greater than the one measured in pure buffered aqueous media. On the other hand, a dramatic enzyme denaturation took place making use of solvents at higher log P-value. Experiments carried out during the 24-h operation clarified that the reaction yield does not depend solely on solvent polarity. Acid phosphatase and beta-glucosidase, which are less resistant than beta-fructofuranosidase to temperature and shear in buffered solutions, showed especially significant enhancement of catalytic activity when hydrolysis was performed with the addition of acetates (50% v/v).

Acetates↗
PubMed1991

Enzyme immobilization using a cellulose-binding domain: properties of a beta-glucosidase fusion protein.

Using molecular genetic techniques, a fusion protein has been produced which contains the cellulose-binding domain (CBD) of an exoglucanase (Cex) from Cellulomonas fimi fused to a beta-glucosidase (Abg) from Agrobacterium sp. The CBD functions as an affinity tag for the simultaneous purification and immobilization of the enzyme on cellulose. Binding to cellulose was stable for prolonged periods at temperatures from 4 degrees C to at least 50 degrees C, at ionic strengths from 10 mM to greater than 1 M, and at pH values below 8. The fusion protein can be desorbed from cellulose with distilled water or at pH greater than 8. Immobilized enzyme columns of the fusion protein bound to cotton fibers exhibited stable beta-glucosidase activity for at least 10 days of continuous operation at temperatures up to 37 degrees C. At higher temperatures, the bound enzyme lost activity. The thermal stability of the fusion protein was greatly improved by immobilization. Immobilization did not alter the pH stability. Except for its ability to bind to cellulose, the properties of the fusion protein were virtually the same as those of the native enzyme.

Adsorption↗
PubMed1994

Enzymatic synthesis of trisaccharides and alkyl beta-D-glucosides by the transglycosylation reaction of beta-glucosidase from Fusarium oxysporum.

Purified beta-glucosidase from Fusarium oxysporum catalyses hydrolysis and transglycosylation reactions. By utilizing the transglycosylation reaction, trisaccharides and alkyl beta-D-glucosides were synthesized under optimal conditions in the presence of various disaccharides and alcohols. The yields of trisaccharides and alkyl beta-D-glucosides were 22-37% and 10-33% of the total sugar, respectively. The enzyme retained 70-80% of its original activity in the presence of 25% (w/v) methanol, ethanol and propanol. Thus, beta-glucosidase from F. oxysporum appears to be an ideal enzyme for the synthesis of useful trisaccharides and alkyl beta-D-glucosides.

Alcohols↗
PubMed1983

The cohydrolases in human spleen that stimulate glucosyl ceramide beta-glucosidase.

A family of beta-glucosidase-stimulating proteins (called cohydrolase SPH-I here) was isolated from bovine, Gaucher human and control human spleens. All preparations exhibited a similar pattern of four major electrophoretic bands in polyacrylamide when stained with the cationic dye, Stains-All. The bovine bands migrated more rapidly, while the two types of human cohydrolase migrated very similarly. The two human preparations differed in several respects: the concentration was much higher in Gaucher spleen; the Gaucher factors eluted a little earlier from gel permeation and decyl agarose columns; much more of the cohydrolase was bound by a concanavalin A column; the control bands stained less intensely in gels than the Gaucher bands. Antibodies raised in rabbits to bovine cohydrolase reacted with all three preparations. All four bands from Gaucher cohydrolase showed similar ability to stimulate glucosidase and to bind the antibodies. It is evident that the cohydrolases from control and Gaucher spleens are similar in many respects, yet differ in some secondary fashion, possibly in carbohydrate content. It is suggested that Gaucher cohydrolase is formed from normal cohydrolase by the nonenzymatic action of cellular glucose over a period of many years, due to slowed catabolism of the cofactor.

Animals↗
PubMed1991

Purification and characterisation of a beta-glucosidase (cellobiase) from a mushroom Termitomyces clypeatus.

A beta-glucosidase with cellobiase activity was purified to homogeneity from the culture filtrate of the mushroom Termtomyces clypeatus. The enzyme had optimum activity at pH 5.0 and temperature 65 degrees C and was stable up to 60 degrees C and within pH 2-10. Among the substrates tested, p-nitrophenyl-beta-D-glucopyranoside and cellobiose were hydrolysed best by the enzyme. Km and Vm values for these substrates were 0.5, 1.25 mM and 95, 91 mumol/min per mg, respectively. The enzyme had low activity towards gentiobiose, salicin and beta-methyl-D-glucoside. Glucose and cellobiose inhibited the beta-D-glucosidase (PNPGase) activity competitively with Ki of 1.7 and 1.9 mM, respectively. Molecular mass of the native enzyme was approximated to be 450 kDa by HPLC, whereas sodium dodecyl sulphate polyacrylamide gel electrophoresis indicated a molecular mass of 110 kDa. The high molecular weight enzyme protein was present both intracellularly and extracellularly from the very early growth phase. The enzyme had a pI of 4.5 and appeared to be a glycoprotein.

Basidiomycota↗
PubMed1993

Thermostable beta-glucosidase and beta-xylosidase from Thermotoga sp. strain FjSS3-B.1.

A beta-D-glucosidase and a beta-D-xylosidase were purified to homogeneity from the thermophilic eubacterium Thermotoga sp. strain FjSS3-B.1. Both enzymes were largely cell-associated and were probably associated with the 'toga' structures of this organism. Using SDS-PAGE they were found to have M(r) values of 75,000 and 92,000, respectively. The beta-glucosidase was active against cellobiose, sophorose and gentiobiose with Km values of 59 mM, 2.7 mM and 6 mM, respectively. The beta-xylosidase had a Km of 2 mM for xylobiose, showed strong activity against p-nitrophenyl alpha-L-arabinofuranoside and p-nitrophenyl alpha-L-arabinopyranoside, but was subject to strong substrate inhibition by p-nitrophenyl beta-D-xylopyranoside. Both enzymes were extremely thermostable, with half-lives of several hours at 98 degrees C. The thermostabilities of both enzymes were increased further by the addition of either trehalose or betaine.

Betaine↗
PubMed1996

Apyrase and alpha-glucosidase in the salivary glands of Aedes albopictus.

An apyrase and an alpha-glucosidase were detected in the salivary glands extracts of adult Aedes albopictus. The apyrase is a 61,000 Da secreted protein that hydrolyses ATP and ADP. This protein is synthe-sized in adults and is preferentially accumulated in the distal lateral lobes of the female salivary glands. The alpha-glucosidase is a secreted 67,000 Da protein. This enzyme is synthesized during adult life and accumulated in the proximal-lateral lobes of both males and females. The results are discussed and compared with data previously obtained with Aedes aegypti salivary glands.

Aedes↗
PubMed1991

Physical characterization of isozymes of endo-beta-1,4-glucanase and beta-1,4-glucosidase from Aspergillus species.

Electrophoretic data revealed the presence of various isozymes of endoglucanase and beta-glucosidase, the number of which varied from one to three in various species of the genus Aspergillus. pH 5.0 was optimum for all the isozymes whereas metal ion treatment showed complete inhibition of almost all the isozymes by Hg2+ and partial inhibition by Ca2+ and Co2+ of isozymes of both the enzymes. An alteration in the electrophoretic mobility of isozymes of beta-glucosidase was also noticed in some species with Hg2+ treatment.

Aspergillus↗
PubMed1990

Sequences and homology analysis of two genes encoding beta-glucosidases from Bacillus polymyxa.

The nucleotide sequences of the bglA and bglB genes encoding beta-glucosidases from Bacillus polymyxa have been determined. Both genes contain coding regions of 1344 bp, corresponding to polypeptides with Mrs of 51,643 and 51,547, respectively. Patterns of codon usage indicate that both genes are expressed at a low frequency. Previous data suggested that the proteins encoded by bglA and bglB were intra- and extracellular enzymes, respectively; however, neither of the two deduced amino acid sequences has N termini with the typical features of a leader peptide. The proteins encoded by bglA and bglB show remarkable homology to each other and to other beta-glucosidases (Bgl) and beta-galactosidases (beta Gal). On the basis of the observed homologies, we can define two groups of microbial Bgl: one of them, type I, including most bacterial Bgl, and type II, including enzymes from different yeast species and one from Clostridium thermocellum. Likewise, at least two groups of beta Gal can be distinguished: type I, including enzymes homologous to type-I Bgl, and type II, showing no homology to any of the previous groups.

Amino Acid Sequence↗
PubMed1987

Subfractionation of the dansylated derivatives of glucosyl galactosyl hydroxylysine by liquid chromatography and its application to a specific alpha-1,2-glucosidase assay.

The dansyl derivative of glucosyl galactosyl hydroxylysine (GGH) was separated into two components, as GP-I (monodansyl GGH) and GP-II (didansyl GGH) by paper chromatography. GP-I was further fractionated into four peaks (a, b, c and d) by reversed-phase liquid chromatography. These peaks corresponded to the dansyl derivatives at the alpha-amino (a and b) and epsilon-amino (c and d) groups of their hydroxylysine residues. There is the possibility that the fractions for b and d are diastereoisomers of a and c, respectively, since the monodansyl derivative from human urine consists of a and c. GP-II was fractionated into two peaks, e and f, which may possibly be diastereoisomers of each other. Treatment of the a, b, c and d fractions with crude chicken liver enzyme resulted in the preferential cleavage of a and b and the production of monodansyl galactosyl hydroxylysine. Components c and d were also cleaved slowly, resulting in the production of monodansyl hydroxylysine by the successive action of beta-galactosidase on dansyl galactosyl hydroxylysine. The detected alpha-glucosidase activity was strongly inhibited by free mannosamine. The method developed using the monodansyl GGH fraction a (or b) and high-performance liquid chromatography facilitated the detection of alpha-1,2-glucosidase, which acts specifically toward GGH even in a crude enzyme preparation.

Animals↗
PubMedDate not supplied

Computed tomography and magnetic resonance imaging of affected muscle in childhood acid alpha-glucosidase deficiency: a case report.

A 13-year-old boy with the juvenile type of acid alpha-glucosidase deficiency is presented. Muscle CT scans performed before muscle biopsy revealed high image density over the entire rectus femoris, and partial high density over the iliopsoas, adductor magnus and tibialis anterior. MRI of the rectus femoris in the transaxial plane showed high image intensity over the entire length of the muscle in both T1- and T2-weighted images. A biopsy revealed a surprising histological difference between the rectus femoris, which showed pronounced vacuolar myopathy with excessive glycogen, and the vastus lateralis, in which deposition of glycogen was minimal and the CT image indicated a normal muscle density. The findings in this case suggest that CT scanning and MRI are useful in recognizing muscle involvement in acid alpha-glucosidase deficiency, which is characterized by images of increased density compared to normal muscle, presumably because excessive deposition of glycogen and lysosomal membranes cause high X-ray absorption on CT and high signal intensity on MRI.

Adolescent↗
PubMed2004

Expression, purification, crystallization and preliminary X-ray analysis of strictosidine glucosidase, an enzyme initiating biosynthetic pathways to a unique diversity of indole alkaloid skeletons.

Strictosidine beta-D-glucosidase, a plant enzyme initiating biosynthetic pathways to about 2000 monoterpenoid indole alkaloids with an extremely large number of various carbon skeletons, has been functionally expressed in Escherichia coli and purified to homogeneity in mg scale. Crystals suitable for X-ray analysis were found by robot-mediated screening. Using the hanging-drop technique, optimum conditions were 0.3 M ammonium sulfate, 0.1 M sodium acetate, pH 4.6 and PEG 4000 (10%) as precipitant buffer. The crystals of strictosidine glucosidase belong to the space group P42(1)2 with unit cell dimensions of a=157.63, c=103.59 A and diffract X-rays to 2.48-A resolution.

Catharanthus↗
PubMed2004

Probing the aglycon binding site of a beta-glucosidase: a collection of C-1-modified 2,5-dideoxy-2,5-imino-D-mannitol derivatives and their structure-activity relationships as competitive inhibitors.

A range of new C-1 modified derivatives of the powerful glucosidase inhibitor 2,5-dideoxy-2,5-imino-D-mannitol has been synthesised and their biological activities probed with the beta-glucosidase from Agrobacterium sp. Ki values are compared with those of previously prepared close relatives. Findings suggest dramatic effects exerted by the aglycon binding site on substrate/inhibitor binding.

Binding, Competitive↗
PubMed2006

Fine tuning of beta-glucosidase inhibitory activity in the 2,5-dideoxy-2,5-imino-D-mannitol (DMDP) system.

Based on our extensive studies of D-glucosidase inhibiting 2,5-dideoxy-2,5-imino-D-mannitol derivatives, we have been trying to create a series of fluorescent derivatives with a view to an 'inhibitory activity ruler' based on competitive displacement reactions of non-fluorescent inhibitors by fluorescent ones and vice versa, which can be performed and followed in microtiter plates or on-chips. Thus, a set of compounds was assembled with Ki values between 2 nM and 1 microM against Agrobacterium sp. beta-glucosidase.

Imino Pyranoses↗