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PubMed2000

[Variability determination in chromatin condensation and seminal alpha glucosidase with relation with the spermiogram].

BACKGROUND: Sperm functional tests as an addition to semen analysis have been used to study the fertilization ability of spermatozoa. Besides the usual variability of the seminal analysis an individual variability in the results of functional tests has been recently found. AIM: To evaluate in a three months period, the individual variability of sperm parameters and sperm maturation using the chromatin condensation test and epidydime a-glucosidase (that allows to discriminate obstructive processes). MATERIAL AND METHOD: The evaluation was carried out in two donors (12 samples) apparently in good health. One of them presented evident semen analysis alterations (donor 1) and the other was considered normal under the WHO standards (donor 2). RESULTS: The averages for donor 1 were: Sperm count 24 x 106 sperm/ml (range 10-58 x 106 sperm/ml), morphology 31.8% (range 30-35%), total motility 33% (range 20-42%), sperm maturation 38% (range 28-78%), a-glucosidase 8.65 (U/ml (range 5-10 (U/ml). The averages for donor 2 were: Sperm count 96 x 106 sperm/ml (range 50-140 x 106 sperm/ml), morphology 32.2% (range 30-35%), total motility 69% (range 58-78%), sperm maturation 17% (range 7-30%), a-glucosidase 36.9 (U/ml (range 20-82 (U/ml). CONCLUSIONS: These results show that significant variations can be found in the sperm parameters and in seminal plasma a-glucosidase; however these variations are generally maintained at the normal or abnormal ranges for each individual, except the sperm morphology that was constant and with low variation in both donors. The determination of the chromatin condensation in the semen analysis gives an additional information about the grade of sperm maturation and would be of great value for differentiating between sperm samples that show similar morphology values.

Adult↗
PubMed2001

The diagnostic value of seminal a-glucosidase enzyme index for sperm motility and fertilizing capacity.

OBJECTIVE: To find out the diagnostic value of seminal a-glucosidase enzyme index in the ejaculated semen samples of proven-fertility and primary infertility patients, for the sperm motility and fertilizing capacity. METHODS: The study which lasted approximately 2 years was carried out in the Andrology Department of the Arab Fertility Center, Jeddah, Kingdom of Saudi Arabia. Eighty-five healthy male patients (age 25-38 years) were admitted into the study. They were divided into 2 main groups as proven-fertility group and primary infertility group. Each group was again subdivided into 4 classes based on the sperm concentrations. The sperm motility assessment was carried out quantitatively by Semi automated Computer assisted Semen analysis using Autosperm analyzer. Simultaneously, a-glucosidase enzyme index was determined in all the semen samples. RESULTS: The results were tabulated as per the standard sperm motility grades of the World Health Organisation, under the classified sperm concentrations of the study. The progressive motility grades were compared with the enzyme index of a-glucosidase in both the groups. The total progressive motility was found higher in the high-density (classes I and II) than the low-density (classes III and IV) semen samples. The enzyme index readings of the various classes of sperm concentrations were significant (p<0.05) and showed a stepwise fall from 89% +/-9% to 52%+/-3% in the proven fertility group. Although, a similar trend has been observed (48%+/-5% to 20%+/-2%) in the primary infertility group, the enzyme index class II sperm concentration (44%+/-6%) was not found significant with class 1 (48%+/-5%) sperm concentration, but the significance was achieved with the other 2 classes. The readings of enzyme index between the groups were found highly significant (p, 0.001). CONCLUSION: The enzyme index of a-glucosidase estimations in semen samples may indicate a positive correlation with progressive motility and fertilizing capacity of spermatozoa and may serve as diagnostic value in individuals showing normal levels of sperm concentration and serum androgen.

Adult↗
PubMedDate not supplied

[Change in the alpha-glucosidase activity of cattle muscle tissue during slow autolysis].

Changes in the alpha-glucosidase activity of the cattle muscular tissue (oxen eye muscle of loin) were evaluated during storage at 2 degrees. Under these conditions both lysosomal and extralysosomal alpha-glucosidase activities underwent no significant changes during a long period of time (12 days). Activity of lysosome-bound alpha-glucosidase was about 10% of total enzyme activity in the homogenate; the remaining part of alpha-glucosidase was contained outside lysosomes.

Animals↗
PubMed1992

The cation-independent mannose 6-phosphate receptor is not involved in the polarized secretion of lysosomal alpha-glucosidase from Caco-2 cells.

In the human adenocarcinoma cell line Caco-2 a substantial amount of a precursor form of the lysosomal enzyme alpha-glucosidase is not segregated into lysosomes, but instead secreted from the apical membrane. In this study we addressed the question whether this process is mediated by mannose 6-phosphate receptors. The subcellular distribution of the cation-independent mannose 6-phosphate receptor was studied by means of electron microscopic immunocytochemistry. The bulk of label was found in the perinuclear region in electron-lucent and dense vesicles, some of the latter bearing a coat. Receptor-containing dense vesicles were also found throughout the cytoplasm. In the apical part of the cells, label for the receptor was present over the surrounding membrane and the interior vesicles of multivesicular bodies, but not over lysosomes. Label on the plasma membrane was mainly restricted to the apical domain. In contrast to alpha-glucosidase, the secreted forms of the lysosomal enzymes cathepsin D, beta-hexosaminidase and beta-glucuronidase are mainly found in the basolateral medium. Enzyme activity measurements and immunoprecipitation of metabolically labeled cells showed that incubation with NH4Cl leads to an enhanced secretion of these enzymes into the basolateral medium, but has no effect on the basolateral secretion of alpha-glucosidase. In addition, NH4Cl caused a minor decrease in the secretion of these enzymes from the apical side and had little or no effect on the secretion of alpha-glucosidase.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonium Chloride↗
PubMed2003

The influence of methyl jasmonate and beta-glucosidase on induction of apple tree resistance mechanisms to two-spotted spider mite (Tetranychus urncae Koch.).

The objective of the research was to determine the influence of methyl jasmonate (JA-Me) and beta-glucosidase on the mechanisms of apple tree resistance to T. urticae like antibiosis and non-preference. The experiments were conducted on leaves of Close and Jester apple cultivars in laboratory conditions. Leaves were treated with: 1. solution of 0.1% JA-Me in 0.05% Triton X-100 (by spraying); 2. beta-glucosidase dissolved in 0.1 M citrate buffer at pH 6 (by petiole); 3. 0.05% solution of the Triton X-100 (by spraying); 4. 0.1 M citrate buffer at pH 6 (by petiole); 5. non-treated leaves. In the no-choice test, application of JA-Me on leaves of apple trees caused reducing of number of eggs laid up during three days of the experiment. In the choice test, which was carried out for determination of non-preference mechanism of resistance, there was not significant differences between number of mites on leaves treated with JA-Me compared to leaves treated with beta-glucosidase, and to non-treated leaves after 24 hours from solutions application. However, at the same experiment, females of T. urticae laid the least number of eggs on leaves treated with JA-Me. Analysis conducted using liquid chromatography method, revealed higher level of phenolic compounds on leaves treated with JA-Me compared to check and leaves treated with beta-glucosidase. Thus, it appears that JA-Me may be regarded as elicitor of induced resistance of apple tree to two-spotted spider mite.

Acetates↗
PubMed2004

Isolation and characterization of alpha-glucosidase inhibitor from the fungus Ganoderma lucidum.

An alpha-glucosidase inhibitor, SKG-3, was isolated from the fruiting bodies of Ganoderma lucidum and its physico-chemical properties were characterized. It was a highly specific and effective reversible inhibitor of alpha-glucosidase. It showed very potent inhibitory activity against alpha-glucosidase with an IC50 value of 4.6 micro g/ml, but no activity for any other glycosidases tested. Enzyme activity could be recovered upon dialysis, thus providing evidence for the reversibility of the inhibition. A Lineweaver-Burk plot indicated that the SKG-3 inhibition of alpha-glucosidase was competitive.

Binding, Competitive↗
PubMed2005

Effect of media composition and growth conditions on production of beta-glucosidase by Aspergillus niger C-6.

The hydrolytic activity of fungal originated beta-glucosidase is exploited in several biotechnological processes to increase the rate and extent of saccharification of several cellulosic materials by hydrolyzing the cellobiose which inhibits cellulases. In a previous presentation, we reported the screening and liquid fermentation with Aspergillus niger, strain C-6 for beta-glucosidase production at shake flask cultures in a basal culture medium with mineral salts, corn syrup liquor, and different waste lignocellulosic materials as the sole carbon source obtaining the maximum enzymatic activity after 5-6 d of 8.5 IU/mL using native sugar cane bagasse. In this work we describe the evaluation of fermentation conditions: growth temperature, medium composition, and pH, also the agitation and aeration effects for beta-glucosidase production under submerged culture using a culture media with corn syrup liquor (CSL) and native sugar cane bagasse pith as the sole carbon source in a laboratory fermenter. The maximum enzyme titer of 7.2 IU/mL was obtained within 3 d of fermentation. This indicates that beta-glucosidase productivity by Aspergillus niger C-6 is function of culture conditions, principally temperature, pH, culture medium conditions, and the oxygen supply given in the bioreactor. Results obtained suggest that this strain is a potential microorganism that can reach a major level of enzyme production and also for enzyme characterization.

Aspergillus niger↗
PubMed2005

[Expression of B-glucosidase gene of Sacchromycopsis fibuligera in Pichia pastoris].

A beta-Glucosidase gene (BGL 1) was amplified with PCR from the total DNA of Sacchromycopsis fibuligera, and was linked with pGEM-T vector. After cut down by restriction enzyme from pGEM-T vector, BGL 1 was inserted into the expression vector pPIC9K of Pichia pastoris in reading frame with alpha-factor secreting signal peptide sequence to construct the recombinant plasmid pSHL9K. The recombinant plasmid pSHL9K was transformed into Pichia pastoris GS115 with electroporation. The recombinant Pichia pastoris strains which could efficiently secret recombinant beta-Glucosidase were selected. The optimum temperature of the recombinant beta-Glucosidase was 50degreesC, and the optimum pH was 5.4. The activity of beta-Glucosidase could reach to 47U/mL in the culture medium.

Pichia↗
PubMed2006

[Screening of glucosidase inhibitors from various fractions of Mulberry leaves].

OBJECTIVE: To search for glucosidase inhibitors of various fractions extracted from mulberry leaves. METHOD: The constituents of mulberry leaves water fraction were prepared by the process of boiling, condensing, precipitating, exchanging with resins and rinsing. In vitro glucosidase inhibitory activities were examined by photometric bioassay derived from rats. To investigate in vivo effect of lowering blood glucose, the mouse blood glucose level was assayed by glucose tolerance experiments. RESULT: The glucosidase inhibitory activities were found in all the constituents of alkaloids, flavones and amyloses, the alkaloid constituent being the strongest. CONCLUSION: The effect of reducing blood glucose of mulberry leaves is related to the inhibitory activities against glucosidase of different constituents.

Alkaloids↗
PubMed1991

[The determination of amylo-1,6-glucosidase in biopsy specimens from human chorion].

This method has been developed for the prenatal diagnosis of a grave hereditary disease, a deficiency of amylo-1,6-glucosidase (A-1,6-G) activity. The methods suggested earlier did not rule out the effects of other glucosidases, that could result in false-positive data if the fetus was involved. The new method for measuring A-1,6-G activity includes sedimentation of acid alpha-glucosidase with rabbit blood antiserum to human placental acid alpha-glucosidase. A-1,6-G activity is estimated from the difference in glucose accrement with limit dextrin and glycogen used as substrates. A-1,6-G activities were measured in 15 chorion samples obtained in the first trimester of pregnancy by the developed method, and normal values of this parameter established, making up 39.77 +/- 8.1 nmol/h per g of protein. The method may be useful in the prenatal diagnosis of type III glycogenosis.

Biopsy↗
PubMed1991

Detection of beta-glucosidase activity on sodium dodecyl sulphate-polyacrylamide gels.

Maize beta-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) was incubated in the presence of SDS concentrations varying from 0.025 to 3.2% at two different pHs (5 and 8), electrophoresed through 10% SDS-polyacrylamide gels, and stained for activity. The zymogram patterns of SDS-treated samples were similar to those of untreated (control) samples. The same samples were also analyzed by native PAGE and IEF, yielding similar patterns for controls and for SDS-treated samples. However, zymogram patterns were severely distorted on IEF gels when SDS concentration of the sample medium was at or above 1.6%. These results suggest that the beta-glucosidase monomer (a 60 kD polypeptide) is either catalytically active or it re-forms dimers upon the removal of SDS during equilibration washes, since the in vivo form of the functional enzyme is thought to be a dimer. The activity of maize beta-glucosidase on SDS-gels after SDS-PAGE does not seem to be limited to this enzyme alone, because beta-glucosidases from other sources (e.g., almond, Trichoderma, and Penicillium) were also active on SDS-gels. Enzyme activity in the presence of SDS or after SDS treatment may be more common than one would expect on the basis of the conventional biochemical dictum that ionic detergents denature and inactivate enzymes. Enzyme activity in the presence of SDS and development of zymograms on SDS-gels offer new approaches to studies of enzyme structure and activity.

Electrophoresis, Polyacrylamide Gel↗
PubMed1991

Glucosidase I, a transmembrane endoplasmic reticular glycoprotein with a luminal catalytic domain.

We have analyzed the functional domain structure of rat mammary glucosidase I, an enzyme involved in N-linked glycoprotein processing, using biochemical and immunological approaches. The enzyme contains a high mannose type sugar chain that can be cleaved by endo-beta-N-acetyl-D-glucosaminidase H without significantly affecting the catalytic activity. Based on trypsin digestion pattern and the data on membrane topography, glucosidase I constitutes a single polypeptide chain of 85 kDa with two contiguous domains: a membrane-bound domain that anchors the protein to the endoplasmic reticulum and a luminal domain. A catalytically active 39-kDa domain could be released from membranes by limited proteolysis of saponin-permeabilized membranes with trypsin. This domain appeared to contain the active site of the enzyme and had the ability to bind to glucosidase I-specific affinity gel. Phase partitioning with Triton X-114 indicated the amphiphilic nature of the native enzyme, consistent with its location as an integral membrane protein, whereas the 39-kDa fragment partitioned in the aqueous phase, a characteristic of soluble polypeptide. These results indicate that glucosidase I is a transmembrane protein with a luminally oriented catalytic domain. Such an orientation of the catalytic domain may facilitate the sequential processing of asparagine-linked oligosaccharide, soon after its transfer en bloc by the oligosaccharyl transferase complex in the lumen of endoplasmic reticulum.

Amino Acid Sequence↗
PubMed1985

Inactivation of alpha-glucosidase by the active-site-directed inhibitor, conduritol B epoxide.

Conduritol B epoxide is an active-site-directed inhibitor of some glucosidases. The inactivation of alpha-glucosidase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) from Monascus ruber by conduritol B epoxide is irreversible and first-order with respect to time and inhibitor concentration. The inactivation is prevented by the presence of the substrate maltose. The pH-dependence of Vmax for maltose indicated the participation of two dissociating groups with pK values of 4.1 and 5.8 in the enzyme-substrate complex. Modification of the alpha-glucosidase with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride led to loss of activity, which suggests that a carboxyl group(s) is located at the active site of alpha-glucosidase.

Binding Sites↗
PubMed1982

[Chemical attachment of p-aminophenylgalactoside to acid alpha-glucosidase from human liver].

Chemical modification of the COOH-groups of acid alpha-glucosidase from human liver by 1-ethyl-3 (3'-dimethylaminopropyl) carbodiimide. HCl in the presence of rho-aminophenyl-beta-D-galactopyranoside was carried out. The presence of covalently bound galactose derivative in the enzyme was followed by changes in the absorption spectra and electrophoretic mobility during polyacrylamide gel electrophoresis and by the ability of modified alpha-glucosidase to interact specifically with castor-bean lectin (RCA II). The modified enzyme retained its catalytic activity towards maltose and did not differ from native alpha-glucosidase in terms of its affinity for this substrate, the Km values for maltose during 5 and 6 mM, respectively. The in vitro changes in the marker specificity of acid alpha-glucosidase against the unchanged catalytic properties of the enzyme are discussed.

Galactosides↗
PubMed1995

beta-Glucosidase families revealed by computer analysis of protein sequences.

This computational study is a summary of how cloned beta-glucosidase subfamilies are organized. Computations were carried out using General Computer Group, Inc. (GCG) package programs. Twenty-two beta-glucosidases belonging to either cellulolytic or non-cellulolytic organisms were identified. The multialignment of a whole beta-glucosidase family is shown. Two sub-families, A and B, were clearly seen to exist. Sub-family A is further subdivided into sub-families A1 and A2. A1 includes vegetal beta-glucosidases and A2 includes prokaryotic enzymes. Sub-family B has three new sub-families, B1, B2, and B3. The enzymes in B2 are of yeast and/or fungi. Aspartic (D), glutamic (E) and histidine (H) residues, which are thought to be a part of the mechanism of the enzymatic hydrolysis are conserved. The well conserved amino acid sequences of the sub-family A are ITENGA; QUIEGA; HVD; and NEP. The well conserved amino acid sequences of the sub-family B are: SDW; and YN(R,K)(V,L)N.

Amino Acid Sequence↗
PubMed1995

Production and some characteristics of beta-glucosidase in Diaporthe (Phomopsis) helianthi.

Diaporthe (Phomopsis) helianthi Munt.-Cvet. et al. is an important phytopathogenic fungus which causes stem canker of sunflower. When grown in submerged cultures in the presence of milled wheat chaff as a carbon source this phytopathogen produced extracellular and intracellular beta-glucosidases. The optimum pH of these enzymes was 4.8. The temperature of crude intracellular beta-glucosidase activity was at 60 degrees C, whereas the optimum activity of crude extracellular beta-glucosidase was observed in a wide range of temperature between 40 and 70 degrees C. Although, extracellular and intracellular beta-glucosidase activities had identical pH and similar temperature optima, the thermal stability of the intracellular enzyme was significantly higher.

Extracellular Space↗
PubMed1993

Conserved structural features in glycoprotein processing glucosidase I from several tissues and species.

Glucosidase I initiates the processing of the oligosaccharide, Glc3Man9GlcNAc2, in newly assembled glycoproteins by excising the distal alpha 1,2-linked glucosyl residue in the oligosaccharide. Earlier, the enzyme purified from the ER of rat and bovine mammary gland has been found to have M(r) of 85 kDa, as examined by SDS-PAGE along with a domain structure in which a 39 kDa lumenally-oriented region is anchored to the ER through a transmembrane segment and a short cytoplasmic tail. These studies were further extended to include the enzyme from several different tissues of the rat, mouse, guinea pig and bovine mammary glands, sheep liver and pig kidney. Using anti-rat glucosidase I antibody as a probe and several biochemical parameters such as SDS-PAGE analysis, trypsin-catalyzed digestion, ConA-binding, endo H susceptibility and peptide mapping analysis by cleavage of the tryptophanyl peptide linkages within the enzyme, it was found that glucosidase I in all of the tissue sources examined has an M(r) of 85 kDa and is cross-reactive to anti-rat glucosidase antibody. The enzyme is a high mannose glycoprotein, and has domain features in its structure; the enzyme from mouse, rat, guinea pig and bovine mammary glands and sheep liver is sequentially cleaved by trypsin to generate fragments of 69, 55 and 39 kDa. The rate of release of the different fragments differs for different sources, indicating some evolutionary changes in its primary structure. The trypsin-released fragments from pig kidney enzyme are 69, 45 and 29 kDa in size, identical to the same observed earlier for pig liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Pompe's disease--acid alpha-glucosidase deficiency--a review].

The importance of the role of acid alpha-glucosidase in the lysosomal degradation of glycogen has been emphasized because the deficiency of this enzyme in glycogenosis type II causes glycogen accumulation in lysosomes. Three clinical variants are distinguished. The infantile type has its onset shortly after birth and is known as generalized glycogen storage disease. The adult variant manifests itself mostly after the second decade of life and is characterized by progressive skeletal muscle weakness. The other is childhood type which is usually fatal by the second decade of life. Many biochemical reports of acid alpha-glucosidase have been published. Martiniuk et al reported the cDNA and amino acid sequence of human acid alpha-glucosidase. In prior studies, they reported that the lysosomal acid alpha-glucosidase was polymorphic with three alleles. The rarer allele GAA2 allozyme had a lower affinity for glycogen and starch. We also reported the enzyme heterogeneity in its affinity to Sephacryl S-200 gel. Whereby the enzyme separated into two fractions, S1 and S2. Each fraction contained 76 kDa and 67 kDa components on SDS/PAGE. The spleen enzyme consisted mainly of S1 fraction, containing only a 76 kDa component. In previous extensive studies, different mutations of Pompe's disease have been inferred from alterations in biochemical parameters. More recently Martiniuk et al, Hoefsloot et al and Van der Ploeg et al reported the analysis of cDNA and mRNA. These studies have revealed an absence or abnormal size of mRNA in large numbers of patients and altered restriction endonuclease fragments in a few patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗