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)

Dinitrophenol (DNP)-beta-glucuronidase and mannosylated anti-DNP IgG, which are endocytosed by the mannose receptor and delivered to lysosomes, were previously developed as probes for examination of fusion between early endosomes in a cell-free system. In this study, these probes were found to be transported by intact cells to endocytic vesicles with heavy buoyant density at different rates, as determined by Percoll gradient fractionation of cell homogenates. There was a concomitant loss of in vitro fusion activity as the ligands moved to dense compartments. In monensin-treated cells, DNP-beta-glucuronidase was retained in a light compartment corresponding to intracellular vesicles capable of fusion in vitro. Pulse-chase studies using a DNP-derivatized transferrin-alkaline phosphatase conjugate showed that a recycling ligand was always found in light intracellular vesicles that were capable of fusion to early endosomes in vitro. In contrast to cell-free systems, intact cells sequentially labeled with DNP-beta-glucuronidase and then mannosylated anti-DNP IgG showed ligand mixing in both early and late endocytic compartments. Treatment with nocodazole or colchicine did not affect the rate of DNP-beta-glucuronidase transport to heavy vesicles in intact cells, however, the extent of ligand mixing in late endosomes was decreased by microtubule disruption. Using sequentially labeled cells split into two groups, we directly compared ligand mixing in vitro to mixing by intact cells. Fusion alone does not mediate increases in vesicle density, since DNP-beta-glucuronidase/anti-DNP IgG complexes formed in vitro were found in light vesicles, while intact cells showed immune complexes predominantly in heavy vesicles. These results suggest that the density shift is an initial step in targeting to lysosomes.
 ...
PMID:Endosomal density shift is related to a decrease in fusion capacity. 180 9

Polymorphonuclear leukocytes (PMN) exposed to highly purified human lactoferrin (from colostrum) exhibit an increased random motility (at least 2.5-fold) and are primed to produce more superoxide [12.1 +/- 1.2 nmol O2-/min/10(6) PMN preincubated with lactoferrin (0.5 mg/ml) against 6.4 +/- 2.3 with cells without lactoferrin after FMLP stimulation]. The action of lactoferrin seemed to be specific, because it could be abolished by simultaneous addition of antilactoferrin antibody. Addition of transferrin and iron salts to PMN was without effect. Between iron-poor and iron-saturated lactoferrin there was no difference in influence on PMN function except for a higher FMLP stimulated superoxide production by iron-saturated lactoferrin. Aggregation, degranulation (beta-glucuronidase, lysozyme), and bacterial killing were not influenced by lactoferrin. Incubation of monocytes and monocyte-derived macrophages with lactoferrin did not alter their motility or their superoxide production rates. Our findings indicate that PMN become more effective after exposure to lactoferrin by having a greater motility and producing superoxide at a faster rate.
 ...
PMID:Influence of lactoferrin on the function of human polymorphonuclear leukocytes and monocytes. 184 51

The accumulation of ten metals in turpentine-induced abscesses of different ages has been studied in rats. The maximum metal concentration ratio between the abscesses and the non-inflamed contralateral muscle was greater than 1 for all the metals studied, the lowest being 2.5 for Zn, and the highest 36 for Th. The ratio remains greater than 1 for more than 28 days for all metals except Ga. There is a marked increase of beta-glucuronidase activity in the inflamed tissue which correlates well with the metal concentration. In contrast the acid phosphatase activity was reduced for the first few days after turpentine injection and never rose above the normal muscle activity. The metals showing the highest uptake in the inflamed lesion appear to be those which are transported in the blood as a transferrin complex.
 ...
PMID:The localization of metallic radionuclides in abscesses in rats. 706 40