Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diphosphonates are known to inhibit bone resorption in tissue culture and in experimental animals. This effect may be due to their ability to inhibit the dissolution of hydroxyapatite crystals, but other mechanisms may be important. Since lysosomal enzymes have implicated in the process of bone resorption, we have examined the effect of several phosphonates and of a polyphosphate (P20,2) on lysosomal hydrolases derived from rat liver and rat bone. Dichloromethylene diphosphonate strongly inhibited acid beta-glycerophosphatase (EC 3.1.3.2) and acid p-nitrophenyl phosphatase (EC 3.1.3.2) and to a lesser degree (in descending order) acid pyrophosphatase (EC 3.1.3.-), arylsulfatase A (EC 3.1.6.1), deoxyribonuclease II(EC 3.1.4.6) and phosphoprotein phosphatase (EC 3.1.3.16) of rat liver. Inhibition of acid p-nitrophenyl phosphatase and arylsulfatase A was competitive. Ethane-1-hydroxy-1, 1-diphosphonate did not inhibit any of these enzymes, except at high concentrations. Neither dichloromethylene diphosphonate nor ethane-1-hydroxy-1, 1-diphosphonate had any effect on beta-glucuronidase (EC 3.2.1.31), arylesterase (EC 3.1.1.2) and cathepsin D (EC 3.4.23.5). Of several other phosphonates tested only undec-10-ene-1-hydroxy-1, 1-diphosphonic acid inhibited acid p-nitrophenyl phosphatase strongly, the polyphosphate (P20, I) had little effect. Acid p-nitrophenyl phosphatase in rat calvaria extract behaved in the same way as the liver enzyme and was also strongly inhibited by dichloromethylene diphosphonate, but not by ethane-1-hydroxy-1, 1-diphosphonate. It is suggested that the inhibition of bone resorption by dichloromethylene diphosphonate might be due in part to a direct effect of this diphosphonate on lysosomal hydrolases.
 ...
PMID:The effect of several diphosphonates on acid phosphohydrolases and other lysosomal enzymes. 17 70

The reliability of enzyme histochemical observations of activities of acid hydrolases was investigated with a combined histochemical and biochemical study. Specimens of m. soleus, m. plantaris, m. gastrocnemius and diaphragm of normal and of vitamin E deficient rabbits were used. For the histochemical investigation, activity and localization of acid phosphatase, beta-glucuronidase, leucine aminopeptidase and E600 resistant non-specific arylesterase were examined with semipermeable membrane techniques. For the biochemical investigation, activity of acid phosphatase, beta-glucuronidase, cathepsin D, acid maltase and neutral maltase was determined. By means of stastical calculations the enzyme activities demonstrated with histochemical techniques were compared with the enzyme activities determined with biochemical techniques. In the present communication the histochemical findings are reported and discussed. From the histochemical findings it appeared that activity of the acid hydrolases investigated is strongly increased in both a granular and a diffuse pattern in skeletal muscle of vitamin E deficient rabbits. The statistical calculations of the histochemical findings clearly reveal that the increased activity of one acid hydrolase was highly significantly paralleled by an increased activity of a second acid hydrolase. Moreover the probability that the activity of all other histochemically studied acid hydrolases was significantly increased was rather high. The increase in activity of the acid hydrolases studied was the same in muscles with an aerobic or an anaerobic metabolism. Moreover there was no difference in activity and localization of the acid hydrolases in aerobic type I and anaerobic type II fibres. The localization of acid phosphatase and beta-glucuronidase activity muscle fibres mostly coincided. In cases where these enzymes were localized both centrally and in the subsarcolemnal areas of the muscle fibres, the activity of E600 resistant naphtholesterase was usually, and the activity of leucine aminopeptidase was exclusively located in the subsarcolemnal areas. All of the examined acid hydrolases were found to be present in the inflammatory exudate and in the connective tissue.
 ...
PMID:Evaluation of histochemical observations of activity of acid hydrolases obtained with semipermeable membrane techniques: a combined histochemical and biochemical investigation 1. The histochemical investigation. 35 53

A method for the isolation of plasma membranes from an experimental murine ependymoblastoma is described. In this procedure, 5'-nucleotidase was used as the plasma membrane marker, since cytochemical methods demonstrated that the enzyme was present on this subcellular structure only. The final plasma membrane preparation showed a 15-fold enrichment in 5'-nucleotidase activity and a 17-fold enrichment in the activity of phosphodiesterase I, another plasma membrane marker. The specific activity of beta-glucuronidase (lysosomal enzyme) was twice that of the whole homogenate, the specific activity of arylesterase (microsomal enzyme) was similar to that of the whole homogenate and succinate dehydrogenase (mitochondrial marker) was not detected. Electron microscopy of this fraction showed vesicles on which 5'-nucleotidase activity could be demonstrated. The subcellular distribution of [3H]amphotericin B per mg of protein was similar in the plasma membrane preparation and in the whole homogenate. It is concluded that, in ependymoblastoma, amphotericin B shows no selective affinity for the plasma membrane.
 ...
PMID:Isolation of plasma membranes from murine ependymoblastoma and subcellular distribution of amphotericin B in this tumor. 85 31

In this communication results are presented of an investigation in which the activity of the hydrolytic enzymes acid phosphatase, beta-glucuronidase, non specific arylesterase, microsomal arylsulphatase, beta-galactosidase, beta-N-acetylglucosaminidase, acid alpha-glucosidase and aminopeptidase M are demonstrated in tissue sections with simultaneous- and post-coupling azo-techniques. Semipermeable membrane techniques are used to hamper enzyme diffusion during the incubation period. From the histochemical and biochemical findings it appeared that an advantage of the post-coupling techniques over the simultaneous-coupling techniques is that inactivation of the enzymes by the coupling reagents is avoided. On the other hand post-coupling techniques are subject to product inhibition. With kinetic inhibition studies it is found that for microsomal arylsulphatase and non-specific arylesterase this product inhibition is non-competitive. This product inhibition may be a problem for histochemical quantitative post-coupling techniques for the determination of acid hydrolase activity.
 ...
PMID:Diazonium inactivation in simultaneous-coupling and product inhibition in post-coupling azo-techniques for demonstrating activity of acid hydrolases. 620 67

The efficiency of the membrane methods of Meijer (1972) and Lojda (1973) in histochemical lysosome tracing was studied and compared with the results of a preparation technique developed by us, employing fresh-frozen celloidin-coated sections; in addition, these methods were compared with results obtained with conventional formalin-sucrose-fixed livers. The lysosomes were traced by reactions for ACPase, beta-glucuronidase, arylesterase and acid-beta-galactosidase activity in rat livers systematically harvested at different time points of occurence of their maximal and minimal activities during the 24-h period, thus indicating a heterogeneity of lysosomes. 3. Optimal results with respect to the morphological appearance of lysosomes were obtained in fresh-frozen celloidin coated sections. This preparation method also caused no enzyme inhibition or loss, thus delivering comparatively the strongest reactions in livers and in enzyme models. 4. Day-time-dependent extralysosomal enzyme activities regularly occur in hepatocytes. Extralysosomal localizations however, are not a consequence of technically induced enzyme diffusion; they are best visualized in celloidin-coated sections; the membrane method produces less satisfactory results, and formalin-sucrose-fixed livers were least satisfactory.
 ...
PMID:Histochemical tracing of lysosomal enzymes. Improved preparation technique for acid phosphatase, beta-glucuronidase, acid-beta-galactosidase, and arylesterase in rat liver. 679 81

Zenarestat, (3-(4-bromo-2-fluorobenzyl)-7-chloro-2,4-dioxo-1,2,3,4- tetrahydroquinazolin-1-yl) acetic acid, an aldose reductase inhibitor is metabolized mainly to the glucuronide in rat and man. The glucuronide was purified from urine of volunteers after ingestion of zenarestat. The structure of the glucuronide was confirmed by LC-MS and NMR as 1-O-acyl-beta-glucuronide. This compound was unstable at physiological pH, being converted to its structural isomers and the aglycone with half-life of 25 min at pH 7.4 and 37 degrees C in aqueous solution. Enzymatic hydrolysis of the glucuronide was studied in urine, blood and tissues. beta-Glucuronidase in human urine contributed little to the hydrolysis of the glucuronide, while in rat urine at pH 6, it was degraded by beta-glucuronidase and the formation of zenarestat was clearly faster than its formation in buffer at pH 6. In both rat and human blood, these reactions were accelerated by albumin, although rat red blood cells may also contribute. The rate of degradation was not affected by red blood cell membrane, haemoglobin, globulin, esterases or beta-glucuronidase. Arylesterase in rat liver, arylesterase and acetylcholinesterase in the kidney, and beta-glucuronidase in both tissues may contribute. Thus, enzymatic degradation of zenarestat 1-O-acyl-beta-glucuronide is dependent not only on pH and temperature but also on species and the type of tissue or body fluid.
 ...
PMID:Enzymatic hydrolysis of zenarestat 1-O-acylglucuronide. 802 35

To determine whether the activities of certain hydrolases (arylesterase, beta-glucuronidase, cathepsin L, plasminogen activators, arginase, glutaminase, asparaginase and adenosine deaminase) are changed during pregnancy, three groups of 15 apparently healthy women (aged 18-38 years) in their first, second and third trimester of pregnancy were compared to a control group formed of 15 non-pregnant women of similar ages. Enzyme and specific activities gradually increased from the first to the end of the third trimester of pregnancy for arylesterase and beta-glucuronidase, these increases being statistically significant (P < 0.01) in comparison to controls. However, as regards cathepsin L and plasminogen activators, the greatest increase was found in the second trimester. Arginase, glutaminase and asparaginase activities were very low and not distinguishable from the controls. In conclusion, differences in the activities of several hydrolases have been found in the sera of healthy pregnant women in comparison to controls.
 ...
PMID:Variation in serum arylesterase, beta-glucuronidase, cathepsin L and plasminogen activators during pregnancy. 893 58

The activities of 21 enzymes (belonging to four classes of enzymes) involved in different metabolic pathways were assayed in blood sera of healthy young and adult/elderly groups of humans, rats and pigs, to determine whether activity changes coinciding with changes in age and aging could be detected. In all three species analysed, measurable activities (performed by highly specific and sensitive techniques, generally spectrofluorimetric procedures) were found, usually following a decreasing order of: among glycosidases, beta-N-acetylglucosaminidase (NAG) > alpha-L-fucosidase > alpha-mannosidase > beta-glucuronidase > beta-galactosidase > alpha-galactosidase. In addition, among esterases very high values were found for arylesterase and acid phosphatase. By contrast, no measurable activity was found for the remaining enzymes assayed (8 hydrolases, 1 oxidoreductase, 3 transferases and 1 lyase). In the elderly group of humans, significantly higher activities (P < or = 0.05) were found for NAG, alpha-mannosidase and beta-glucuronidase in comparison to the adult and young groups. However, several activities in rats and all activities in pigs decreased with age. In conclusion, differences in the activities of 6 lysosomal glycosidases and 2 esterases (but no significant differences for another 13 enzymes belonging to several enzyme classes) are found in the sera of healthy humans, rats and pigs. These differences coincide with changes observed in aging.
 ...
PMID:Evaluation of the activities of eight lysosomal hydrolases in sera of humans, rats and pigs of different ages. 948 85