Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glycosidases are lysosomal enzymes that participate in the catabolism of glycoproteins and other glycoconjugates, and in some way may modify their activity in situations in which carbohydrate metabolism could be altered, such as the case of obesity. Using a fluorometric assay, a study was made of four glycosidase activities: N-acetyl-beta-D-hexosaminidase (NAG), alpha-mannosidase and alpha- and beta-glucosidase in the serum, pancreas, liver and kidney of 22 Zucker fa/fa genetically obese rats and of 23 fa/? controls, both with ages ranging between 13 and 15 weeks. After 12-14 hours fast and prior anaesthesia with sodium pentobarbital intraperitoneally, blood and the afore-mentioned organs were removed for enzymatic study of the serum and the organs after homogenization and centrifugation. In the serum a statistically significant increase in alpha-mannosidase (p < 0.0001) and alpha-glucosidase (p < 0.02) activities was found in the fa/fa obese rats as compared with the controls. No statistically significant differences were found in serum hexosaminidase activity between the two groups, and no serum beta-glucosidase enzymatic activity was detected. In liver, a decrease was observed in hexosaminidase (p < 0.002) and alpha-glucosidase (p < 0.01) activities in the obese rats as compared with the controls. In whole pancreas an increase was found in alpha-glucosidase activity in the obese rats with respect to the controls (p < 0.001), with no statistically significant differences in the hexosaminidase, alpha-mannosidase and beta-glucosidase activities.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enzymatic glycosidase activities in experimental obesity. 142 11

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

The activities of seven glycosidases (six lysosomal and one cytosolic) were determined in B- and T-lymphoid cells differing by immunological phenotypes and occurring at various differentiation stages. The cells were isolated from the circulating blood, bone marrow or spleens of patients with various forms of lymphoproliferative disorders. The glycosidase activities varied significantly depending on the phenotype. The highest activity of all glycosidases was observed in cells with a common lymphoid cell progenitor phenotype. In cells having the phenotype of mature T- and B-cells the glycosidase activities were comparatively low. The changes in all glycosidase activities depending on the phenotype and differentiation stage usually occurred in the same direction; however, the degree of elevation or decline of activities of individual glycosidases was different. The activities of N-acetyl-beta-D-hexosaminidase and alpha-D-mannosidase changed dramatically, whereas the changes in the activity of cytosolic neutral alpha-D-glucosidase were less apparent. These data suggest that lysosomal glycosidases play specific roles in lymphoid cell differentiation.
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PMID:[Glycosidase activity in phenotypically different pathologic lymphoid cells, found at various stages of differentiation]. 193 50

The changes in the activities of certain lysosomal hydrolases, viz., beta-glucuronidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase, alpha-glucosidase, alpha-galactosidase, alpha-mannosidase, cathepsin B, cathepsin D, and collagenolytic cathepsin, in serum and heart of rats subject to myocardial infarction with isoproterenol, were studied during the periods of peak infarction and recovery. The activities of all the enzymes assayed exhibited a significant increase both in serum and in heart at peak infarction stage and these levels returned to normal during the stage of recovery and repair. The infiltration of inflammatory cells at the infarct regions and the altered lysosomal fragility are probably responsible for the increased activity of the enzymes studied. This may also bring about the catabolism of connective tissue constituents as reported in literature.
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PMID:Influence of isoproterenol-induced myocardial infarction on certain glycohydrolases and cathepsins in rats. 201 10

The activities of alpha- and beta-glucosidase, beta-galactosidase and beta-N acetylglucosaminidase were assessed at acidic pH by fluorimetry using the appropriate 4-methylumbelliferyl substrate in four Mycoplasma species (M. pneumoniae, M. gallisepticum, M. hominis and M. capricolum) and in Acholeplasma laidlawii. The glycosidase activities were in a low range (0.1-4.2 nmole per h per mg protein) with the exception of higher activities of beta-N-acetylglucosaminidase in A. laidlawii. The enzyme levels of a virulent and a nonvirulent strain of M. pneumoniae were comparable. Despite the very sensitive assay, neuraminidase activity was not detected in M. pneumoniae and M. gallisepticum. No induction of alpha-glucosidase could be demonstrated for M. pneumoniae or A. laidlawii. At least part of the glycosidase activities was localized in the membrane fraction of all mycoplasmas studied. This may support the hypothesis that pathogenic mycoplasmas, being membrane parasites, may modify, by their glycosidases, some host cell glycoconjugates. However, our study did not distinguish the pathogenic mycoplasmas to possess a characteristic glycosidase profile.
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PMID:Glycosidase activities of mycoplasmas. 211 90

1. Boar semen was separated on a Percoll density gradient into three populations; a low-density band of immature sperm cells containing a cytoplasmic droplet and a high-density doublet band formed by spermatozoa without a cytoplasmic droplet. 2. In these three cell populations four acid hydrolases were determined, viz. (1) alpha-glucosidase; (2) alpha-mannosidase; (3) beta-galactosidase; (4) beta-hexosaminidase. 3. The release of the hydrolases (1), (2) and (3) from cytoplasmic droplet containing spermatozoa was stimulated whereas the release of beta-hexosaminidase was inhibited by calcium ions. 4. The results suggest that acid alpha-glucosidase, alpha-mannosidase and beta-galactosidase are situated in the acrosome whereas acid beta-hexosaminidase is localized predominantly in the cytoplasmic droplet of boar spermatozoa. 5. We conclude that beta-hexosaminidase should prove useful as a biochemical marker for cytoplasmic droplet containing spermatozoa and hence for the number of immature sperm cells in boar semen.
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PMID:Isolation and characterization of boar spermatozoa with and without a cytoplasmic droplet. 214 Aug

A biochemical scheme was developed by which strains of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus can reliably be distinguished from within the "Streptococcus milleri group." Strains identified as S. intermedius were differentiated by the ability to produce detectable levels of alpha-glucosidase, beta-galactosidase, beta-D-fucosidase, beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, and sialidase with 4-methylumbelliferyl-linked fluorogenic substrates in microdilution trays after 3 h of incubation at 37 degrees C, together with the production of hyaluronidase. Strains of S. constellatus and S. anginosus were differentiated by the production of alpha-glucosidase and hyaluronidase by the former and the production of beta-glucosidase by the latter. The majority of strains of the S. milleri group obtained from dental plaque were identified as S. intermedius, as were most strains isolated from abscesses of the brain and liver. Strains of S. constellatus and S. anginosus were from a wider variety of infections, both oral and nonoral, than were strains of S. intermedius, with the majority of strains from urogenital infections being identified as S. anginosus.
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PMID:Phenotypic differentiation of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus strains within the "Streptococcus milleri group". 238 Mar 75

Cells of Entamoeba histolytica grown over a period of four days contained NADP+-dependent alcohol dehydrogenase exclusively inside the cells. No activity of this enzyme could be found in the growth medium after harvesting the cells. Under the same conditions, acid phosphatase, beta-N-acetylglucosaminidase, esterase, alpha-glucosidase, and different amylases of the parasite were found both inside the cells and in the medium. The activities present in the cell homogenate and in the medium before and after growth of the amoebas were partially separated by gel filtration on Sephadex G150 and G75, respectively. The comparison of the elution diagrams revealed that NADP+-dependent alcohol dehydrogenase, acid phosphatase, esterase, and amylases occurred as multiple forms inside the cells. These activities, as well as beta-N-acetylglucosaminidase and alpha-glucosidase, were released into the extracellular environment to a different degree. The enzymes originating from the parasite were identified and distinguished from those of the ingredients of the growth medium according to their molecular mass and pH optimum. Furthermore, the amoebic origin of the secreted enzymes was shown on the basis of their inhibition by antibodies prepared against the supernatant fraction of the homogenate.
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PMID:Secretory hydrolases of Entamoeba histolytica. 245 86

Recently developed computer programs, including secondary structure and epitopic site predictions, have been used to align lysosomal proteins for maximum homology, based on conservative interchanges, and the aligned sequences have been searched for potential sites for posttranslational modification, glycosylation, and binding and catalysis of substrate. The homology and prediction of the posttranslational modification of the alpha- and beta-subunits of hexosaminidase is in good agreement with previous observations, and an explanation of the differing substrate specificities of the two subunits is advanced. We show that the striking homology between alpha-glucosidase and isomaltase is reflected in the apparent conservation of the active site in both enzymes. Nonhomologous regions have been examined in detail in a search for binding sites for glycogen and maltose, and two such sites have been tentatively identified. A highly redundant consensus sequence for the phosphorylation of mannose in lysosomal proteins, YXX(Y, W, or F), is suggested.
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PMID:Homology of lysosomal enzymes and related proteins: prediction of posttranslational modification sites including phosphorylation of mannose and potential epitopic and substrate binding sites in the alpha- and beta-subunits of hexosaminidases, alpha-glucosidase, and rabbit and human isomaltase. 246 89

The nephrotoxicity of ribostamycin and gentamicin was compared by urinalysis using 18 parameters. When a dose of 40 mg/kg per day was administered intramuscularly to Fischer rats for 14 days, ribostamycin caused little change of parameters in urine volume, urine osmolality, urine protein, maltase and beta 2-microglobulin. A slight increase with ribostamycin was observed in alpha-fucosidase, beta-N-acetylglucosaminidase, leucine aminopeptidase, lactic dehydrogenase (LDH) and potassium, and a moderate increase was observed in acid phosphatase and alkaline phosphatase. On the other hand, gentamicin caused a large alteration in most parameters. Both antibiotics caused a change of the isoenzyme pattern of LDH1-5, but the pattern with ribostamycin was much closer to the normal pattern than with gentamicin. When a dose of 80 mg/kg of ribostamycin was compared with 10 mg/kg of gentamicin, alteration of urinary parameters was almost comparable. Histopathological observations of the kidney specimens of rats given 40 mg/kg per day showed no histological damage with ribostamycin except for a slight increase and enlargement of lysosomes of the proximal epithelial cells. However, significant histological damage was observed with gentamicin, consistent with the results obtained from urinalysis. Renal accumulation of ribostamycin at a single dose of 20 mg/kg was three times less than that of gentamicin. Ribostamycin caused slightly less nephrotoxicity in rats than kanamycin and far less than dibekacin at an equal dosage of 40 mg/kg per day for 14 days.
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PMID:Comparative nephrotoxicity of ribostamycin and gentamicin in rats evaluated by urinalysis. 259 Dec 99


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