Acid glycohydrolase in Chinese hamster (Cricetulus griseus) with spontaneous diabetes--V. Subcellular distribution in the kidney.

1. Seven renal glycohydrolases were measured in four subcellular fractions prepared from highly inbred aglycosuric (AV-line) and glycosuric (XA-line) Chinese hamsters. 2. alpha-D-galactosidase and beta-D-galactosidase were highest in the nuclear (N) and supernatant (S) fractions; both fractions showed reduced activities in the XA animals. 3. alpha-D-mannosidase was chiefly a particulate enzyme and its decrease in XA animals was evident in N, lysosomal-mitochondrial (LM) and mitochondrial-microsomal (MM) fractions. 4. No significant difference in N-acetyl-beta-D-glucosaminidase was found in any of these subcellular fractions between AV and XA animals. 5. Although total alpha-L-fucosidase and beta-D-fucosidase levels were similar in AV and XA kidneys, a difference was observed in the S fraction. 6. beta-D-glucuronidase was virtually absent in N and LM fractions and the S fraction of AV kidneys showed higher activity than the XAs.     

Membrane anchoring and surface distribution of glycohydrolases of human erythrocyte membranes

The membrane anchoring of the following glycohydrolases of human erythrocyte plasma membranes was investigated: alpha- and beta-D-glucosidase, alpha- and beta-D-galactosidase, beta-D-glucuronidase, N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase, and alpha-L-fucosidase. Optimized fluorimetric methods for the assay of these enzymes were set up. Treatment of the ghost preparation with 1.0 mol/l (optimal concentration) NaCl caused release ranging from 4.2% of alpha-D-glucosidase to 70% of beta-D-galactosidase; treatment with 0.4% (optimal concentration) Triton X-100 liberated 5.1% of beta-D-galactosidase to 89% of alpha-D-glucosidase; treatment with 1.75% (optimal concentration) octylglucoside yielded solubilization from 6.3% of beta-D-galactosidase to 85% of alpha-D-glucosidase. Treatment with phosphoinositide-specific phospholipase C caused no liberation of any of the studied glycohydrolases. These results are consistent with the notion that the above glycohydrolases are differently anchored or associated with the erythrocyte plasma membrane, and provide the methodological basis for inspecting the occurrence of these enzymes in different membrane microdomains.     

Purification and biological characterization of N-acetyl beta-D glucosaminidase from Bufo arenarum spermatozoa

Fertilization in Bufo arenarum requires the sperm to penetrate the egg envelopes. The incubation of isolated vitelline envelopes with sperm induces the acrosome reaction, releasing proteases and glycosidases to the media. In the present work N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, beta-D-glucosidase, alpha-D-mannosidase, alpha-L-fucosidase, and alpha-D-glucosidase activities are measured in spermatozoa. N-acetyl-beta-D-glucosaminidase is the major sperm glycosidase activity assayed. However, N-acetyl-beta-D-galactosamine show competitive inhibitory effect. The glycosidase pH optimum is 3.5 being inhibited at pHs higher than 7.5. In our study, N-acetyl-beta-D-glucosaminidase is the only glycosidase that in vitro binds to vitelline envelopes in conditions that resemble natural fertilization media. The isolation of the active enzyme will allow studies of its role in fertilization. The enzyme has been purified in a two-step procedure. After native gel electrophoresis, the activity-stained band was cut out and the eluted enzyme was finally subjected to ConA-sepharose chromatography. In SDS-PAGE, the denatured enzyme migrates as a single band with a molecular mass of 45 kDa. Furthermore, analysis by size-exclusion on HPLC showed a peak of activity at around 45 kDa. Preliminary localization studies showed higher relative activity in the acrosomal content. In addition, 10% of the N-acetyl-beta-D-glucosaminidase activity was associated with the reacted sperm. By in vitro fertilization assay, it was observed that the inhibition of the enzyme results in the inhibition of fertilization. This last study shows that N-acetyl-beta-D-glucosaminidase plays an important role in toad fertilization.     

Chronobiological study of several enzymes of lysosomal origin in human plasma

The possible occurrence of circadian and circannual rhythms in the plasma concentrations of the following enzymes of lysosomal origin was assessed: beta-D-N-acetylglucosaminidase (EC 3.2.1.30) beta-D-glucuronidase (EC 3.2.1.31), beta-D-glucosidase (EC 3.2.1.21), beta-D-galactosidase (EC 3.2.1.22), alpha-D-galactosidase (EC 3.2.1.23), alpha-L-fucosidase (EC 3.2.1) and alpha-D-mannosidase (EC 3.2.1.24). The circadian rhythm was studied in 16 women (aged: 17-24 years) and 13 men (age: 23 years) volunteers; the circannual rhythm, in 10 women and 8 men (age: 20-25 years). The circadian rhythm was detected in all the tested enzymes of women, and only in alpha-D-galactosidase, beta-D-glucosidase, alpha-D-mannosidase and beta-D-acetylglucosaminidase of men. A statistically significant difference between genders in the circadian rhythm was exhibited by beta-D-galactosidase (MESOR; amplitude) beta-D-glucosidase (MESOR; amplitude; acrophase) beta-D-N-acetylglucosaminidase, beta-D-glucuronidase and alpha-D-galactosidase (MESOR) and alpha-L-fucosidase (amplitude, acrophase). A circannual rhythm was detected in all the tested enzymes with the exception of beta-D-glucuronidase and beta-D-N-acetylglucosaminidase; no statistically significant difference between genders was detected. The group rhythms of some of the enzymes (alpha-D-galactosidase, beta-D-glucosidase, beta-D-galactosidase) showed similar values of both circadian and circannual acrophases, suggesting that they may subjected as a group to the same chronobiological coordination, possibly mediated by hormones. The chronobiological rhythms of lysosomal enzymes were different from those of lactate dehydrogenase and alpha 1-antitrypsin, indicating that these rhythms are not merely reflecting fluctuations of the water content of plasma. No in-phase relationship was observed between the circadian and circannual rhythms of plasma cortisol and those of the tested lysosomal enzymes, excluding a direct chronobiological and possibly functional relationship between this hormone and lysosomal enzymes.     

Acid glycosidases of normal cattle lymphocytes and in chronic lympholeukemia

The activity of five acid glycosidases was determined in lymphocytes from normal animals and animals with chronic lymphocytic leukemia. It was shown that alpha-D-mannosidase activity in leukemic lymphocytes was 5 times lower (p less than less than 0.001) and alpha-D-glucosidase activity was 2 times lower (p less than 0.01) than in normal controls. The progress of the disease and the increase in leukocyte count were accompanied by the decrease in alpha-D-mannosidase activity. No differences have been found in alpha-D-mannosidase properties (thermostability, Km values, ZnSl2 activation) in normal and leukemic lymphocytes.     

Glycosphingolipid glycosyl hydrolases and glycosidases of synchronized human KB cells.

KB cells were synchronized by a double thymidine block procedure. An investigation was made of the activities of alpha-L-fucosidase (EC 3.2.1.51), alpha-D-galactosidase (EC 3.2.1.22), beta-D-galactosidase (ec 3.2.1.23), alpha-D-glucosidase (EC 3.2.1.20), beta-D-glucosidase (EC 3.2.1.21), alpha-D-mannosidase (EC 3.2.1.24), beta-D-N-acetylgalactosaminidase (EC 3.2.1.53), and beta-D-N-acetylglucosaminidase (EC 3.2.1.52) from synchronized cultures, using appropriate artificial substrates. Ceramide glucosidase (EC 3.2.1.45) and ceramide trihexosidase levels (EC 3.2.1.47) were also investigated at various stages in the cell cycle, using appropriate glycosphingolipid substrates. Whereas each of these enzymes exhibited some activity throughout the cell cycle, peak activity (2- to 6-fold increase) occurred late in the S phase. Two molecular forms of ceramide glucosidase (optimal activity at pH 4.0 and pH 6.0) and two forms of ceramide trihexosidase (pH 4.0 and pH 7.5) were identified. Peak levels of the forms that preferred the relatively acid pH occurred earlier in the S phase of the cell cycle than those of the forms that were more active at the higher pH. The possibility that the forms with optimal activity at pH 4 are precursors of those with optimal activity at pH 6 to 7.5 is discussed. Precipitation of beta-galactosidase of synchronized KB cells with specific antibody revealed that changes in the activity of this enzyme during the cell cycle were the result of fluctuations in the amount of the enzyme.     

Comparative study on the activity, pH optimum and thermal stability of some glycosidases and acid phosphatase from pig and mule leukocytes.

1. alpha-D-mannosidase, beta-D-galactosidase, alpha-L-fucosidase, beta-N-acetylgalactosaminidase, alpha-D-glucosidase and acid phosphatase activities were studied in circulating blood leukocytes from Sus scropha var. domestica L. (pig) and Equus asinus x caballus (mule) by spectrophotometric procedures using p-nitrophenyl derivatives as substrates and three different buffer solutions. 2. The highest specific activity corresponds to acid phosphatase. The specific activities of the glycosidases, all relatively close together in all cases, were low in comparison with that of phosphatase. 3. Generally, each of the above-mentioned enzymes shows one common peak for the pH optimum between 3.5 and 6.0, except alpha-D-glucosidase, which shows two peaks. 4. The pH optima values are generally similar in three buffer solutions employed. 5. Specific activities of the studied enzymes show a parallelism in leukocytes from both pig and mule. Also, this parallelism is observed in their pH optima values. 6. Thermal stability of alpha-D-mannosidase is high whereas that of acid phosphatase is low, in both materials. For other enzymes, differences in the thermal stability was observed according to their source.     

Comparative studies on six blood serum glycosidases from several mammalian species.

1. Peripheral blood serum alpha-D-galactosidase, beta-D-galactosidase, beta-D-glucosidase, alpha-D-mannosidase, beta-D-xylosidase and beta-D-glucuronidase have been studied with a comparative point of view from several mammalian species: Bos taurus L. (bull), Capra hircus L. (goat), Sus scropha var. domestica L. (pig) and man. 2. Fluorimetric and spectrophotometric procedures were used for determination of enzyme activities and pH optima. 3. Glycosidase activity was generally higher with fluorescent substrates than with chromogenic substrates. 4. alpha-D-mannosidase was the most active with both fluorescent and chromogenic substrates. 5. All the studied enzymes had the same pH optimum (4.0) when the chromogenic substrates were used. 6. pH optima of these glycosidases ranged from 3.0 to 5.5 when the fluorescent substrates were used.     

Detection and differentiation between mycotoxigenic and non-mycotoxigenic strains of two Fusarium spp. using volatile production profiles and hydrolytic enzymes

Volatile profiles and hydrolytic enzyme production by one non-mycotoxigenic and three mycotoxigenic strains of Fusarium moniliforme and F. proliferatum, grown in vitro for up to 96 h on a grain medium at 25 degrees C/0.95 water activity, were examined for differentiation of isolates. After spore lawn inoculation, measurements were made after 48, 72 and 96 h by sampling the head space above cultures with an electronic nose system using a 14 sensor surface polymer array, and by extraction and quantification of hydrolytic enzymes. There was good reproducibility of volatile patterns between replicates of the same treatment. Principal component analysis indicated that discrimination could be achieved between the uninoculated controls, the non-mycotoxigenic strain and the mycotoxin-producing strains for both species after 48 h. The total and specific activity of three out of seven enzymes (beta-D-glucosidase, alpha-D-galactosidase and N-acetyl-beta-D-glucosaminidase) were found to increase significantly in the non-mycotoxigenic when compared with the toxigenic strains of both species after 72 h. Activities of the others (beta-D-fucosidase, alpha-D-mannosidase, beta-D-xylosidase and N-acetyl-alpha-D-glucosaminidase) were not significantly different between strains. The study has shown for the first time that it is possible to differentiate between mycotoxigenic and non-mycotoxigenic strains of such spoilage fungi based on their volatile production patterns using an electronic nose system. These results have significance in the development of methods for the early detection of toxin-producing spoilage moulds in the food industry.     

Acid glycohydrolase in Chinese hamster with spontaneous diabetes. VII. The lack of short-term glucose-effect in cultured kidney cells

An epithelial cell line, designated CHK-ACE, was established from the kidney of a spontaneously diabetic Chinese hamster from the highly inbred AC line. CHK-ACE was separated into two sublines, CHK-ACE-100 and CHK-ACE-400, by successive passages in 100 and 400 mg/dl glucose respectively. Extra- and intracellular activities of N-acetyl-beta-D-glucosaminidase and beta-D-galactosidase were measured in these cultures after exposure to varying concentrations of glucose (100, 200, 300 and 400 mg/dl) for one passage and 10% heated fetal calf serum for 6.5 h before enzyme measurements were taken; no apparent dependence on medium-glucose concentration was found. In serum-free medium, the time-dependent release of both N-acetyl-beta-D-glucosaminidase and beta-D-galactosidase was sustained for up to 24 h; no significant difference in their activities was found between CHK-ACE-100 cultures grown in 100 and 400 mg/dl glucose for one passage.     

Urinary lysosomal hydrolases in mucolipidosis II and mucolipidosis III.

Investigation of the binding characteristics of acid beta-D-galactosidase, N-acetyl-beta-D-glucosaminidase, alpha-D-galactosidase and alpha-L-fucosidase from patients with mucolipidosis II and mucolipidosis III to concanavalin A--Sepharose 4B revealed a 2--10-fold decrease in the proportion of enzyme activities from patients with mucolipidoses II and III that adsorbed on the lectin. Neuraminidase treatment of the unadsorbed enzyme fraction did not significantly increased the proportion of enzyme activities that bound to the concanavalin A--Sepharose 4B. Characterization of acid beta-D-galactosidase from the adsorbed and unadsorbed enzyme fractions of mucolipidosis II and mucolipidosis III patients demonstrated identical apparent Km values of 0.22 mM with respect to 4-methylumbelliferyl beta-D-galactopyranoside, altered pH--activity profiles and heterogeneous isoelectric-focusing patterns. The results of this study support the suggestion of an alteration of a post-translational modification (possibly glycosylation) occurring in mucolipidosis II and mucolipidosis III common to the lysosomal hydrolases that affects the mannoserelated properties of these enzymes.     

L-Ascorbic acid and lysosomal acid hydrolase activities of guinea pig liver and brain

The effects of L-ascorbic acid deficiency on guinea pig hepatic and brain lysosomal hydrolases were examined. In general, hepatic beta-N-acetylhexosaminidase, beta-D-glucoronidase, alpha-D-galactosidase, alpha-D-mannosidase, and acid phosphatase were elevated in scorbutic animals. This appears to be independent of the starved state. Brain beta-D-glucoronidase and acid phosphatase followed a similar pattern to that observed with the liver enzymes, but brain beta-N-acetylhexosaminidase was not affected by L-ascorbic acid decreased the activity of hepatic beta-N-acetylhexosaminiadase was unaffected by dietary treatments although the activity of beta-N-acetylhexosaminidase A tended to increase in the scorbutic animals. Subcellular fractions were obtained from the three groups of animals and the recoveries of protein, beta-N-acetylhexosaminidase, and glucose-6-phosphatase estimated.     

Production of exopolysaccharide by Lactobacillus rhamnosus R and analysis of its enzymatic degradation during prolonged fermentation

The potential of Lactobacillus rhamnosus R for producing exopolysaccharide (EPS) when grown on basal minimum medium supplemented with glucose or lactose was investigated. EPS production by L. rhamnosus R is partially growth associated and about 500 mg of EPS per liter was synthesized with both sugars. The product yield coefficient (Y(EPS/S)) was 3.15 (0.0315 g of EPS [g of lactose](-1)) and 2.88 (0.0288 g of EPS [g of glucose](-1)). It was clearly shown that the amount of EPS produced declined upon prolonged fermentation. Degradation of EPS in fermentation processes was also assessed by measuring its molecular weights and viscosities. As these reductions might have a negative effect on the yield and viscosifying properties of EPS, it was essential to examine possible causes related to this breakdown. The decrease in viscosities and molecular weights of EPS withdrawn at different cultivation times permitted us to suspect the presence of a depolymerizing enzyme in the fermentation medium. Our study on enzymatic production profiles showed a large spectrum of glycohydrolases (alpha-D-glucosidase, beta-D-glucosidase, alpha-D-galactosidase, beta-D-galactosidase, beta-D-glucuronidase, and some traces of alpha-L-rhamnosidase). These enzymes were localized, two of them (alpha-D-glucosidase and beta-D-glucuronidase) were partially purified and characterized. When incubated with EPS, these enzymes were capable of lowering the viscosity of the polymer as well as liberating some reducing sugars. Upon prolonged incubation (27 h), the loss of viscosity was increased up to 33%.     

Enzymic activities in the seminal plasma of normospermic, oligospermic and infertile azoospermic men

Activities of seminal plasma alpha-D-glucosidase, beta-D-galactosidase, alpha-amylase, chymotrypsin-like enzyme and RNAase were studied in normo spermic, oligospermic and non-obstructive azoospermic men. No significant change in the activities of the aforesaid enzymes were found amongst the three catagories, classified according to sperm density.     

Purification and characterization of a strictly specific beta-D-fucosidase from Aspergillus phoenicis.

Although beta-D-fucosidase (beta-D-fucohydrolase, EC 3.2.1.38) has been isolated from various sources, all those enzymes were associated with a high activity of beta-D-galactosidase and/or beta-D-glucosidase. We have purified a specific beta-D-fucosidase in electrophoretically homogeneous form from crude extracts of Aspergillus phoenicis by polyethyleneglycol 8000-phosphate buffer aqueous two-phase separation, and successive chromatography on DEAE-Sephadex A-50, hydroxyapatite, and Sephadex G-100 columns. The molecular weight of the enzyme was estimated to be 57,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 50,000 to 60,000 by gel filtration on Sephadex G-100. The enzyme showed optimum activity at pH 6.0 and 40 degrees C; it was stable in the pH range 5.5-6.5 and below 35 degrees C. The Km and the Vmax values for pNP-beta -D-fucoside were 2.4 mM, and 12.8 mumol.min-1.mg-1, respectively. The enzyme was strongly inhibited by sulfhydryl group reagents, p-chloromercuribenzoate, n-ethylmaleimide, and iodoacetate. It was also inhibited by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, diethyl pyrocarbonate, and N-bromosuccinimide. Thus, -SH and -COOH groups and histidyl and tryptophyl residues were essential for enzyme activity. The purified beta-D-fucosidase showed high specificity toward p-nitrophenyl-beta-D-fucoside. The enzyme was inhibited by D-fucose and D-fucono-gamma-lactone, but not by D-galactose, D-galactono-gamma-lactone, D-glucose, or D-glucono-gamma-lactone; the latter compounds are specific inhibitors of beta-D-galactosidase and beta-D-glucosidase, respectively. Thus, this enzyme is the most strictly specific beta-D-fucosidase when compared with those previously reported.     

Microorganisms that produce alpha-galactosidase, alpha-mannosidase, alpha-fucosidase and beta-acetylglucosaminidase

The capacity to synthesize alpha-D-galactosidase (EC 3.2.1.22), alpha-D-mannosidase (EC 3.2.1.24), alpha-L-fucosidase (EC 3.2.1.51) and beta-D-acetylglucose aminidase (EC 3.2.1.30) was tested among 100 different cultures of soil microscopic fungi and actinomycetes. Two genera of micromycetes, viz. Scopulariopsis and Aposphaeria, which had not been known as producing alpha-D-galactosidase, were found, as well as several new species of the genus Penicillium: Pen. canescens, Pen. claviforme, Pen. cyclopium, Pen. daleae, Pen. frequentans, Pen. piscarum, Pen. simplicissimu, Pen. thomii.     

Synthesis of polyhydroxylated piperidines and evaluation as glycosidase inhibitors

A series of 16 new chiral nonracemic polyhydroxylated piperidines was synthesized utilizing several chiral beta-amino-alcohols. They act as a nitrogen source, chirality inducer and iminium stabilizer, in the desymmetrization of meso-trihydroxylated glutaraldehyde. The biological activity of these compounds towards several glycosidases (alpha-D-glucosidase, alpha-D-mannosidase, alpha-L-fucosidase) has been evaluated.     

Effect of tobramycin and gentamicin on the activity of some glycosidases in rat serum and urine

beta-Galactosidase, alpha-D-mannosidase, alpha-L-fucosidase and N-acetyl-beta-D-glucosaminidase activities were assayed in serum and urine from rats treated with three different doses of the nephrotoxic antibiotic tobramycin (100 mg/kg/day for 5 days, 10 mg/kg/day for 10 days and 5 mg/kg/day for 20 days) and gentamicin (100 mg/kg/day for 5 days). A significant increase of beta-galactosidase, N-acetyl-beta-D-glucosaminidase and alpha-L-fucosidase activities occurred in urine following the administration of high doses of antibiotic. The enzyme activity was dependent on the dose level used. The excretion of alpha-D-mannosidase was atypical and elevated activities were observed on some days but no pattern of excretion of this enzyme was established. No change in any of the four glycosidase activities was found in serum of treated rats. The results obtained when high doses of gentamicin were employed are similar to those obtained with a similar dose of tobramycin. These results indicate that the assay of urinary glycosidase activities provides a useful method for monitoring the nephrotoxicity of antibiotics.     

New syntheses of 1D- and 1L-1,2-anhydro-myo-inositol and assessment of their glycosidase inhibitory activities

The 1D and 1L enantiomers of 1,2-anhydro-myo-inositol (conduritol B epoxide) were synthesised from 1D-pinitol and 1L-quebrachitol, respectively, and their activities were compared in selected glycosidase inhibition assays. The 1D enantiomer was found to be the active isomer, functioning as an irreversible inhibitor of sweet almond beta-D-glucosidase. Neither isomer was active against the alpha-D-glucosidase from Bacillus stearothermophilus or the beta-D-galactosidase from Aspergillus oryzae.     

Synthesis and enzyme-inhibitory activity of methyl acarviosin analogues having the alpha-manno configuration.

Two methyl acarviosin analogues 3a and 4a, having the alpha-manno configuration, and their dihydro derivatives 6a and 7a were synthesised by coupling the protected pseudo-sugar epoxides with methyl 4-amino-4-deoxy- and -4,6-dideoxy-alpha-D-mannopyranoside. Similarly, two analogous compounds 5a and 8a composed of the 1,6-anhydro-beta-D-mannopyranose residues were prepared. Compound 7a showed mild inhibitory activity against Jack bean alpha-D-mannosidase, and 3a was a moderate inhibitor of both alpha-D-mannosidase and yeast alpha-D-glucosidase.