Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.21 (beta-glucosidase)
3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The yeast alpha-mannosidase [EC 3.2.1.24] was purified 1160-fold from the crude extract of the autolysate. The purified preparation was practically free from alpha-glucosidase, beta-glucosidase, alpha-galactosidase, beta-galactosidase, beta-mannosidase, and beta-N-acetylhexosaminidase activities. After the separation of yeast mannan during the purification procedures the enzyme became unstable but could be stored at 5 degrees C for three weeks with 50% loss of activity. The purified enzyme hydrolyzed both aryl and alkyl mannosides, but hydrolysis of yeast mannan proceeded slowly. Yeast mannan and Zn2+ increased the enzyme catalyzed hydrolysis of p-nitrophenyl mannoside, whereas NaN3, monoiodoacetate and methyl alpha-D-mannoside acted as inhibitors. The molecular weight was estimated to be 450,000 by gel filtration.
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PMID:Purification and properties of alpha-mannosidase from bakers' yeast. 33 3

Sphingolipidoses in infancy and adulthood and associated metabolic disturbances are caused by a recessively inherited, circumscribed lysosomal enzyme deficiency in the catabolism of various structural tissue substances. After presenting detailed methods for the quantitative assay of activities of lysosomal hydrolytic enzymes in leukocytes, serum , fibroblasts, urine and organ tissue with the aid of synthetic chromogenic and fluorescent substrates the signigicance of these methods for clinical diagnosis, for the detection of homozygote persons before developing clinical symptoms (preclinical diagnosis), for the preventive prenatal diagnosis and forthe detection of heterozygote carriers is described for the following diseases: Deficiency of hexosaminidase A and B, deficiency of beta-glucosidase, deficiency or arylsulfatase A, deficiency of alpha-galactosidase, deficiency of alpha-glucosidase.
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PMID:[Clinical, preclinical and prenatal diagnosis of congenital sphingolipidoses by determining lysosomal hydrolases (author's transl)]. 41 9

Specific glycosidase activities were determined in samples of gingival crevicular fluid (GCF) collected from eight predetermined sites in two groups, each of 20 adult patients, with either gingivitis or periodontitis. The total activities (as units of enzyme activity per sample) of alpha-L-fucosidase, sialidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase and alpha-glucosidase were significantly greater in the periodontitis group. In contrast, the total beta-mannosidase and hexosaminidase A activities were significantly greater in the gingivitis group, while there was no significant difference in the total alpha-mannosidase activity between the groups. Only the specific activities (as units of enzyme activity per min per microliter of GCF) of beta-mannosidase and hexosaminidase A were significantly different between the groups being greater in the gingivitis group. When used to predict the clinical status of individual periodontal sites, the total enzyme activities had specificity and sensitivity values of 91.9 and 61.3%, respectively. Measurement of glycosidase activities might thus have a role in monitoring the efficacy of periodontal treatment or in predicting future periodontal disease but this will require further investigation.
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PMID:Glycosidase activities in gingival crevicular fluid in subjects with adult periodontitis or gingivitis. 161 Mar 3

About 1200 strains of microorganisms were screened including fungi, actinomyces, and bacteria, in which 237 strains producing the enzyme desired. The results showed that the beta-GlcNAcase and beta-GalNAcase always co-existed in one strain, though may be in different ratio. From strains mentioned above the authors screened out a potent beta-N-acetylhexosaminidase producing strain, Aspergillus tamarii S215, from the soil sample. The optimal conditions for enzyme production were as follows: the microorganisms was inoculated in a 5% wheat bran suspension, cultured at 28-30 degrees C on shaker for 5-6 days. The productivity can be moderately enhanced by the addition of cellobiose or glucosamine or galactosamine or by the extra supplement of (NH4)2SO4 and NH4NO3 as N sources. In the culture filtrate of Asp. tamarii, the alpha, (beta)-galactosidase, beta-glucosidase, alpha-mannosidase and beta-fucosidase were also found.
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PMID:[Screening of beta-N-acetylhexosaminidase forming strains and conditions for enzyme production]. 214 44

The purification of beta-N-acetylhexosaminidase, alpha-glucosidase, alpha-mannosidase and beta-glucosidase from the spent growth medium of Dictyostelium discoideum strain Ax-2 myxamoebae is described. beta-N-Acetylhexosaminidase and alpha-glucosidase were obtained in high yield and as homogeneous preparations whereas the alpha-mannosidase preparation consisted of two electrophoretically distinct isoenzymes. The physical, chemical and kinetic properties of these enzymes are described.
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PMID:The purification and properties of extracellular glycosidases of the cellular slime mould Dictyostelium discoideum. 419 17

Sphingolipidoses are an heterogeneous group of inherited disorders of lipid metabolism affecting primarily the central nervous system. These disorders occur chiefly in the pediatric population, and the degenerative nature of the disease processes is generally characterized by diffuse and progressive involvement of neurones (gray matter) with psychomotor retardation and myoclonus or of fiber tracts (white matter) with weakness and spasticity. Biochemical research has identified the defects in the sphingolipidoses to specific lysosomal enzymes. For example, Niemann-Pick disease lacks sphingomyelinase; Krabbe's disease lacks galactocerebrosidase; Gaucher's disease lacks beta-D-glucosidase; metachromatic leukodystrophy lacks sulfatase; Tay-Sachs disease lacks hexosaminidase A; and generalized gangliosidosis lacks beta-galactosidase. Although there are no currently available modes of rendering corrective therapy in these disorders, a definitive diagnosis is possible both antepartum as well as postpartum. This information provides a sound and accurate basis for genetic counseling.
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PMID:Sphingolipidoses. 555 2

Castanospermine (1,6,7,8-tetrahydroxyoctahydroindolizine) was tested against a variety of commercially available glycosidases and found to be a potent inhibitor of almond emulsin beta-glucosidase, and also to inhibit fungal beta-xylosidase. This alkaloid was inactive on yeast alpha-glucosidase, alpha- or beta-galactosidase, alpha-mannosidase, beta-N-acetylhexosaminidase, beta-glucuronidase, alpha-L-fucosidase. Fifty-percent inhibition of beta-glucosidase required about 10 micrograms/ml of castanospermine. The amount of inhibition was uniform throughout the time course, and the inhibition with regard to substrate concentration (p-nitrophenyl-beta-D-glucopyranoside) appeared to be of the mixed type. Castanospermine was also a potent inhibitor of beta-glucocerebrosidase when assayed with fibroblast extracts using either a fluorimetric or a radioactive assay. Interestingly enough, castanospermine also inhibited the lysosomal alpha-glucosidase, and this inhibition required comparable levels of alkaloid to that required for inhibition of beta-glucocerebrosidase. However, a number of other lysosomal glycosidases were not sensitive to castanospermine (i.e., alpha- or beta-galactosidase, alpha- or beta-mannosidase, alpha- or beta-L-fucosidase, beta-N-acetylhexosaminidase, beta-glucuronidase).
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PMID:Castanospermine, a tetrahydroxylated alkaloid that inhibits beta-glucosidase and beta-glucocerebrosidase. 640 22

Larval and adult Psacothea hilaris feed on mulberry wood and leaves, respectively. High levels of endogenous activity against the major dietary carbohydrates, cellulose, hemicellulose, starch and soluble sugars were secreted in the gut of larvae and adults. Activity against pectin was also high and multiple polygalacturonase (EC 3.2.1.15) components were secreted in the gut of larvae. One glycanase component, beta-EG1, which was primarily an endo-beta-1,4-glucanase (EC 3.2.1.4) and another, beta-EG2, which was mostly an endo-beta-1,4-xylanase (EC 3.2.1.8), were also secreted, while at least four additional components hydrolysed laminarin, lichenin and crystalline cellulose. The beta-glycosidase component beta-GD1 was associated with most of the beta-mannosidase (EC 3.2.1.25) and beta-xylosidase (EC 3.2.1.37) activity secreted in the gut of larvae, while another, beta-GD2, was a beta-glucosidase (EC 3.2.1.21), the activity of which was directed against cellobiose and other beta-linked disaccharides, and a beta-fucosidase (EC 3.2.1.38). A beta-galactosidase (EC 3.2.1.23), which did not hydrolyse lactose, was also secreted, as were distinct beta-N-acetylhexosaminidase (EC 3.2.1.52), trehalase (EC 3.2.1.28), alpha-L-arabinosidase (EC 3.2.1.55), alpha-galactosidase (EC 3.2.1.22) and a minimum of four alpha-glucosidase (EC 3.2.1.20) components, one of which was also likely to be associated with a peak of alpha-mannosidase (EC 3.2.1.24) activity. The alpha-glucosidase components varied in their specificity for alpha-linked disaccharides, but none was active against sucrose, which was hydrolysed by a beta-fructofuranosidase (EC 3.2.1.26) component. Overall average levels of activity in larvae were twice those of adults, but the secretion of individual carbohydrases in both was not regulated in response to the relative abundance of particular carbohydrate components in their respective diets.
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PMID:Diet and carbohydrate digestion in the yellow-spotted longicorn beetle Psacothea hilaris. 1277 Apr 76

Fasciola hepatica secretes proteolytic enzymes and other molecules that are essential for host penetration and migration. This mixture may include enzymes required for the degradation of supramucosal gels, which defend epithelial surfaces against pathogen entry. These contain hydrated mucins that are heavily glycosylated. Excretory-secretory products (ES) from F. hepatica were examined for a range of glycosidase activities, using synthetic 4-methylumbelliferyl glycosides as substrates. The ES product contained at least 8 different glycosidase activities, the most abundant of which were beta-N-acetylhexosaminidase, beta-galactosidase and beta-glucosidase. Alpha-fucosidase, beta-glucuronidase, alpha-galactosidase, alpha-mannosidase and neuraminidase were also present. Beta-N-acetylhexosaminidase and beta-galactosidase were present in multiple isoforms (at least 4), whereas beta-glucosidase appeared to exist as one isoenzyme with a pI < 3.8. All three enzymes had acidic pH optima (4.5-5.0). Ovine small intestinal mucin was degraded by ES at pH 4.5 or 7.0, with or without active cathepsin L, the major protease found in F. hepatica ES. The ability of F. hepatica ES to degrade mucin in the presence or absence of active cathepsin L suggests that cathepsin L is not essential for mucin degradation. The abundance of beta-galactosidase and beta-hexosaminidase in ES supports a role for these enzymes in mucin degradation.
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PMID:Glycosidase activity in the excretory-secretory products of the liver fluke, Fasciola hepatica. 1552 35

The gram-positive soil bacterium Cellulomonas fimi is shown to produce at least two intracellular beta-N-acetylglucosaminidases, a family 20 beta-N-acetylhexosaminidase (Hex20), and a novel family 3-beta-N-acetylglucosaminidase/beta-glucosidase (Nag3), through screening of a genomic expression library, cloning of genes and analysis of their sequences. Nag3 exhibits broad substrate specificity for substituents at the C2 position of the glycone: kcat/Km values at 25 degrees C were 0.066 s(-1) x mM(-1) and 0.076 s(-1) x mM(-1) for 4'-nitrophenyl beta-N-acetyl-D-glucosaminide and 4'-nitrophenyl beta-D-glucoside, respectively. The first glycosidase with this broad specificity to be described, Nag3, suggests an interesting evolutionary link between beta-N-acetylglucosaminidases and beta-glucosidases of family 3. Reaction by a double-displacement mechanism was confirmed for Nag3 through the identification of a glycosyl-enzyme species trapped with the slow substrate 2',4'-dinitrophenyl 2-deoxy-2-fluoro-beta-D-glucopyranoside. Hex20 requires the acetamido group at C2 of the substrate, being unable to cleave beta-glucosides, since its mechanism involves an oxazolinium ion intermediate. However, it is broad in its specificity for the D-glucosyl/D-galactosyl configuration of the glycone: Km and kcat values were 53 microM and 482.3 s(-1) for 4'-nitrophenyl beta-N-acetyl-D-glucosaminide and 66 microM and 129.1 s(-1) for 4'-nitrophenyl beta-N-acetyl-D-galactosaminide.
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PMID:Characterization of a beta-N-acetylhexosaminidase and a beta-N-acetylglucosaminidase/beta-glucosidase from Cellulomonas fimi. 1676 38


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