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

Lysosomal membrane stabilization has been proposed as a mechanism for the anti-inflammatory action of corticosteroid hormones. This hypothesis was based on studies with liver organelles. We studied the action of steroids on intact lysosomes isolated from human peripheral blood polymorphonuclear (PMN) leukocytes. Both androstenedione and progesterone, 10(-3)-10(-5) M, caused leakage of acid hydrolase markers from these organelles, thus resembling their effects on liver lysosomes. But none of the anti-inflammatory steroids tested protected organelle membranes from either detergent lysis (Triton X-100) or heat incubation (37 degrees C, 90 min). Hydrocortisone (HC), HC sodium succinate, HC acetate, HC hemisuccinate, prednisone, and dexamethasone were without detectable stabilizing activity at concentrations of 10(-3)-5 x 10(-8) M. Release of the lysosomal marker, beta-glucuronidase, was not retarded by any of the compounds studied. In addition, PMN leukocyte lysosomes isolated from human volunteers receiving prednisolone were not more stable than control organelles, nor did serum from steroid-treated humans protect intact lysosomes from detergent lysis. Variations in cholesterol and phospholipid contents of liver and PMN leukocyte lysosome membranes could possibly account for the different reactivity to corticosteroids observed. We believe that the anti-inflammatory activity of adrenal corticosteroids can best be explained by their inhibitory effects on cellular metabolism rather than by their direct interaction with lysosomal membranes.
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PMID:Effects of steroid hormones on human polymorphonuclear leukocyte lysosomes. 443 Jul 21

1. Five-day-old anaesthetized rats subjected to slow, prolonged asphyxia (50-55 min) were either allowed to die or resuscitated when at the point of death. Activities of various cerebral acid hydrolases known to be associated with lysosomes were determined in these animals and in littermate controls. 2. Asphyxia to death resulted in a significant increase in the activities of acid phosphatase, cathepsin (pH5.0) and beta-glucuronidase in whole-brain homogenates. 3. The effect of asphyxia on beta-glucuronidase activity was not apparent when the assay was performed in the presence of Triton X-100 (0.1%, v/v). 4. In resuscitated animals whole-brain-homogenate beta-glucuronidase activity showed the greatest increase (31%) 15 min after recovery. After a 60 min recovery period differences between control and asphyxiated animals were no longer apparent. 5. In animals anoxiated to death activities of acid phosphatase and beta-N-acetylglucosaminidase in brain high-speed supernatants were significantly higher than in controls. Acid phosphatase activity was similarly increased in asphyxiated animals resuscitated for 5 or 60 min. 6. It is suggested that the response of the immature rat brain to asphyxia involves a disruption or increased fragility of lysosomal particles.
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PMID:The effect of anoxia on cerebral acid hydrolases in the five-day-old rat. 465 94

1. Homogenates of guinea-pig polymorphonuclear leucocytes were separated by differential centrifugation into six particulate fractions and a soluble fraction. 2. The distributions in these fractions of protein, DNA, succinate dehydrogenase, beta-glucuronidase, peroxidase, alkaline phosphatase, acid phosphatase (against p-nitrophenyl phosphate and beta-glycerophosphate), cathepsin, and catalase were compared. 3. Almost all of the DNA sedimented in the first two pellets, indicating that the nuclei were relatively intact. 4. The four hydrolases and peroxidase showed different distribution patterns, although these activities were previously reported to be localized mainly in the single ;granule' fraction isolated from leucocytes. 5. The particles containing peroxidase, acid phosphatase and alkaline phosphatase all exhibited latency. Maximum activity for each enzyme was obtained at roughly similar concentrations of Triton X-100. 6. The acid phosphatase of these cells was distributed between two populations of particles that differed in both sedimentation characteristics and density. The acid phosphatase(s) of the two populations showed slightly different substrate specificities. This bimodal distribution was not an artifact of the procedure used to elicit the cells. 7. Catalase was recovered almost entirely in the soluble fraction and showed no latency in freshly prepared homogenates. No urate oxidase was detected. 8. We conclude that the ;granule' fraction of the polymorphonuclear leucocyte, as isolated by previous workers, contains at least three, probably more, populations of particles with different enzyme contents, and that these cells probably do not contain peroxisomes.
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PMID:The distributions of some granule-associated enzymes in guinea-pig polymorphonuclear leucocytes. 541 96

1. A partially purified lysosomal preparation was obtained from mouse liver sucrose homogenates by differential and discontinuous gradient centrifugation. 2. Triton X-100 or repeated freezing and thawing of the lysosomal suspension (subfraction B) allowed comparison of free and activated values for acid phosphohydrolase, beta-glucuronidase and N-acetylglucosaminidase in the presence and absence of ascorbate. 3. The distribution of hydrolase activities between supernatant and pellet after high-speed centrifugation was measured and the percentages of total enzyme found in the supernatant were: acid phosphohydrolase, 40.7; beta-glucuronidase, 51; N-acetylglucosaminidase, 39.4. 4. Differential rates of elution of the three hydrolases from the membrane fraction occurred with increasing Na(+) and K(+) concentrations, whereas complex biphasic elution curves were obtained as a function of bivalent cation concentration with Ca(2+) and Mg(2+). 5. Sucrose-density-gradient centrifugation of frozen-and-thawed subfraction B demonstrated highly significant changes in the protein gradient profile in the presence of a low concentration of bivalent cation, indicating membrane aggregation and enzyme-membrane association. 6. The data provide further evidence for the nature of lysosomal enzyme binding and indicate the presence of different enzyme-membrane bonds conferring structure-linked latency upon individual lysosomal enzymes.
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PMID:Effect of cations on structure-linked sedimentability of lysosomal hydrolases. 566 44

1. Two acid phosphatases (beta-glycerophosphatase and phenylphosphatase), acid beta-glucuronidase and cathepsin were demonstrated in the 0.25m-sucrose homogenates from whole calf thyroid tissue and from isolated calf thyroid cells. 2. The main kinetic characters of these enzymes were studied. 3. All these acid hydrolases are partially sedimentable and display a latency that is unmasked by treatment with Triton X-100 and on dilution in hypo-osmotic media. It is concluded that these acid hydrolases belong to the lysosomes.
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PMID:Lysosomal hydrolases in calf thyroid. 596 51

1. The distribution pattern of hyaluronidase in subcellular fractions of bone-tissue homogenates is closely similar to that reported by Vaes & Jacques (1965b) for the other acid hydrolases of this tissue. The highest specific activity of hyaluronidase is also found in the light-mitochondrial fraction. 2. In cytoplasmic extracts of bone, about 60% of the activity of hyaluronidase is latent, and is unmasked by a number of treatments (digitonin, low osmotic pressure, freezing and thawing, Waring Blendor) that unmask the lysosomal beta-glucuronidase in a closely parallel manner. Low concentrations of Triton X-100 render a larger proportion of beta-glucuronidase than of hyaluronidase accessible to external substrates, but release the same proportion of both enzymes in unsedimentable form. 3. These results support the concept of an association of hyaluronidase with lysosomes in bone.
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PMID:Hyaluronidase activity in lysosomes of bone tissue. 604 5

The antigenic composition of the live vaccine strain of Francisella tularensis was investigated. Ether-water extracts, water-soluble material from freeze-pressed bacteria and detergent-eluted material from bacterial envelope were allowed to react in immunodiffusion and immunoelectrophoresis with rabbit antiserum against disintegrated bacteria of the vaccine strain. Ten antigenic factors were distinguished in an ether extract. When the extract was precipitated with ammonium sulphate 15 antigenic factors were distinguished in the precipitate and 14 factors in an ethanol precipitate of the supernatant fluid. In the water extract of freeze-pressed material 17 antigenic factors were found. Comparative immunoelectrophoresis of all these fractions demonstrated a minimum of 20 antigenic factors. When envelope material of the vaccine strain was treated with Triton X-100, three more antigenic factors were found to be solubilized. Thus, a total of 23 antigenic factors were distinguished in the extracts. There was a wide variation in heat and trypsin sensitivity between the antigenic factors. A few of the factors had esterase or alkaline phosphatase activity, whereas acid phosphatase, beta-glucuronidase or peroxidase activities were not found in any of the factors.
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PMID:Antigenic composition of a vaccine strain of Francisella tularensis. 615 69

A simplified and rapid method for simultaneous activity measurements of three lysosomal marker enzymes, acid phosphatase, beta-glucuronidase, and beta-N-acetyl-D-hexosaminidase is described. The incubation is carried out in a single test tube and stopped by adding an alkaline sodium dodecyl sulfate solution, thus avoiding centrifugations and allowing for higher Triton X-100 concentrations in the incubation media. Two products of the beta-glycosidases (phenolphthalein and 2-nitrophenolate) are measured spectrophotometrically at the respective wavelengths (555 and 420 nm), and one of the acid phosphatase products is quantitatively determined by measuring inorganic phosphate.
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PMID:A combined assay of three lysosomal marker enzymes: acid phosphatase, beta-D-glucuronidase, and beta-N-acetyl-D-hexosaminidase. 624 32

Electron-dense material in clear synaptic vesicles in rat cerebral cortex and neuromuscular junctions of frog cutaneous pectoris muscle was demonstrated by using ferrocenyl cationics. Electron-dense spots were usually attached to the inner surface of the vesicular membrane. Control experiments (treatment with Triton X-100 or cetylpyridinium chloride; enzyme digestion with trypsin, hyaluronidase, neuraminidase, sulfatase and beta-glucuronidase) suggested that the electron-dense material is a glycoprotein.
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PMID:Demonstration of electron-dense material in clear synaptic vesicles using cationic ferrocenyl compounds. 633 45

In vitro studies on rat hepatic lysosomal stability, as assessed by release of beta-glucuronidase, were undertaken to demonstrate the comparative influence of surface-active agents which act by various mechanisms. Bile acids, short chain alcohols, acetylsalicylic acid, and Triton X-100 were studied, as well as their interaction with zinc. The detergents and alcohols enhanced release of this acid hydrolase in a dose dependent fashion, but acetylsalicylic acid did not. Zinc antagonized these effects in a non-specific manner. It is postulated that zinc stabilized lysosomes by direct action on the lysosomal membrane, such as by surface protein interactions, but the precise mechanism remains unknown.
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PMID:Modulating effect by zinc on hepatic lysosomal fragility induced by surface-active agents. 738 47


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