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)

A method for the isolation of intact phagocytic vesicles from guinea pig peritoneal-exudate granulocytes and human peripheral-blood leukocytes is presented. After leukocytes ingested the particles of a stable emulsion of paraffin oil, the uningested emulsion was washed away and the cells were homogenized. The homogenate was placed in the middle of a three-step discontinuous sucrose gradient and centrifuged for 1 hr at 100,000 g. The phagocytic vesicles, containing the low density paraffin-oil particles, were simultaneously washed and collected by floatation, while the other organelles, chiefly granules, sedimented through the lower wash layer, and the particle-free supernatant remained in the middle of the gradient. Emulsion particles stained with Oil Red O were employed to assay the rate of phagocytosis and to mark the location of the particles in subcellular fractions. The dye was extracted from washed cells or cell fractions with dioxane and colorimetrically quantified. The purity of phagocytic vesicles obtained by this method was assessed by electron microscopy, chemical analysis, and assay of enzyme composition. Granule-associated enzymes, acid phosphatase, alkaline phosphatase, beta-glucuronidase, and peroxidase were present in the phagocytic vesicles and originated from the granules. Cyanide-resistant NADH (reduced form of diphosphopyridine nucleotide) oxidase was also found. Enzymes associated with the vesicles exhibited latency to Triton X-100. Uptake of particles and the transfer of total protein and phospholipid into phagocytic vesicles occurred simultaneously Accumulation of acid and alkaline phosphatase in the vesicles continued until phagocytosis ceased. Peroxidase, NADH oxidase, and beta-glucuronidase activities in the phagocytic vesicles, on the other hand, were maximal by 30 min and increased little thereafter even when phagocytosis was still going on.
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PMID:Isolation and properties of phagocytic vesicles from polymorphonuclear leukocytes. 410 63

Phagocytic vesicles were obtained by density gradient centrifugation of homogenized rabbit alveolar macrophages that had ingested emulsified paraffin oil contained Oil Red O. The phagocyte vesicles floated and thereby were separated from the soluble fraction and from other cell components which sedimented. The purity of the isolated vesicles was documented by electron microscopy, chemical and enzyme analysis. The vesicles contained 87% of the cell-associated Oil Red O, and were essentially free of DNA, RNA, succinic dehydrogenase, and glucose-6-phosphatase. Acid phosphatase, beta-glucuronidase, and catalase were transferred from the sedimenting fraction to the phagocytic vesicle fraction during phagocytosis, whereas enzyme activities of the soluble fraction remained unchanged. Half of the catalase of resting macrophages was in the pellet fraction and, compared with acid phosphatase, greater amounts of digitonin were required to release full activity. Such differential latency has been described for enzymes of peroxisomes vs. those of lysosomes. Compared with polymorphonuclear leukocyte vesicles studied previously, phagocytic vesicles of macrophages had more electron-dense material and lower Oil Red O:protein, phospholipid:protein, and enzyme:protein ratios. It is thus probable that secondary lysosomes become part of the macrophage vesicle. When paraffin oil particles, the stimulus for phagocytic vesicle formation, were washed away from the macrophages, acquisition of hydrolases by preformed vesicles ceased, i.e. transfer of these enzymes into phagocytic vesicles occurred only during or shortly after the formation of new vesicles. As noted previously by others, the content of acid hydrolases of stimulated alveolar macrophages was doubled in comparison to normal cells. The difference between stimulated and normal macrophages was even more marked when isolated phagocytic vesicles were analyzed. Vesicles from stimulated macrophages had 3-5 times more enzyme activity (per milligram of vesicle protein or per amount of paraffin oil ingested) than did vesicles from normal cells.
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PMID:Isolation and properties of phagocytic vesicles. II. Alveolar macrophages. 501 Nov 3

The rha1 gene from Arabidopsis encodes a small GTP binding protein belonging to the Ypt/Rab family. Transgenic Arabidopsis plants containing the promoter region of the rha1 gene fused to the beta-glucuronidase (gus) reporter gene revealed gus expression limited mainly to the guard cells of stomata, the stipules, and the root tip of young plants. In flowering plants, expression was found predominantly in the receptacle and in guard cells of the different flower organs. High GUS activity could also be seen in callus tissue and developing seeds. No detectable activity was present in other plant tissues; activity could not be induced by various treatments. GUS activity was visualized histochemically using both 5-bromo-4-chloro-3-indolyl beta-D-glucuronide and a newly developed GUS substrate: Sudan II-beta-glucuronide. The latter precipitates as red crystals at the site of GUS activity. Results obtained by the gus analysis were confirmed by whole-mount mRNA in situ hybridization. A hypothesis for the function of the Rha1 protein is discussed.
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PMID:rha1, a gene encoding a small GTP binding protein from Arabidopsis, is expressed primarily in developing guard cells. 830 70