D- Glucuronidases

With phenolphthalein j3-D-glucopyranosyluronic acid as substrate in a human serum jS-D-glucuronidase assay, centrifugation at high speed after addition of alkali was required to minimize blanks.Optimal substrate concentration was 3-6 mM excess substrate was inhibitory. 

The intracellular localization of exogenously supplied human platelet 3-D-glucuronidase in cultured skin fibroblasts derived from a j3-D-glucuronidase-deficient patient was studied.Four cellular fractions were obtained by 

Seven renal glycoside hydrolases have been measured in four subcellular fractions prepared from highly inbred aglycosuric ( F-line) and glycosuric (X4-line) Chinese hamsters (Cricetulus griseus). 3-D-Glucuronidase was virtually absent in nuclear, lysosomal-mitrochondrial fractions and supernatant fractions of A F-kidneys showed higher activity than the XAs. 

Procedures for the large scale isolation of /3-D-glucuronidase from urine of androgen-treated mice carrying Gus, Gus, or Gus structural alleles have 

Okimura, H. Ohmori, Y. Kubota, and I. Yamamoto, Biochem. Pharmacol., 1979, 28, 2729. 

The molecular structure, transformation, and subcellular translocation of multiple forms of jS-D-glucuronidase have been reviewed.  

in Isoenzymes I - Molecular Structure , ed. C. L. Markert, Academic Press, New York and London, 1975, p. 637. 

The level of jS-D-glucuronidase activity in human-skin fibroblasts from patients with Maroteaux-Lamy syndrome has been shown to be normal. The activities and properties of )3-D-glucuronidase in embryonic human-lung (diploid Wl-38) fibroblasts have been reported.  

The non-phagocytic release of jS-o-glucuronidase from human neutrophils by various reagents, including inhibitors of the enzyme, has been investigated.  

A simple procedure for the isolation of j8-D-glucuronidase from extracts of human placenta has used chromatography on concanavalin A immobilized on macroporous agarose.  

Although a reinterpretation of the course of hyperamylasemia during diabetic comas inferred a possible relationship between the levels of )8-D-glucuronidase and amylase, the correlation actually obtained was poor.  

Incubation of normal human fibroblasts with chloroquine at physiological pH released jS-D-glucuronidase activity into the medium, suggesting that chloroquine competes with the enzyme in binding to the cell membrane.  

Ion-exchange chromatography has shown that different molecular forms of jS-D-glucuronidase are present in cultures of fibroblasts from human amniotic fluid the pattern is similar to those in skin fibroblasts and liver tissues.  

Yamasaki, J. Suzuki, and J. Ozawa, Agric. and Biol. Chem. Japan), 1976, 40, 669. 

Wiesmann, S. DiDonato, and N. N. Herschkowitz, Biochem. Biophys. Res. Comm., 

The rate of removal of purified P-D-glucuronidases from rats following intravenous infusion depended on the source of the enzyme. Thus, the P-D-glucuronidase from rat serum was cleared more slowly from circulation than that from rat preputial glands. The lysosomal compartment of rat liver has an important role in the removal of circulating tris and glycoside hydrolases.  

The p-D-glucuronidase from the preputial glands of rats crystallized following fractional precipitation, fractionation in ethanol, and gel filtration. The purified enzyme (12S, mol. wt. 3.2 x 10 ) appeared to be homogeneous on examination by polyacrylamide gel electrophoresis, but electrophoresis in the presence 

P-D-glucopyranosyluronic acid 0.53 mmol 1 ) contains few sulphur-containing amino-acids and 5.7% of carbohydrate consisting of D-mannose, D-glucose, L-fucose, D-galactose, and 2-amino-2-deoxy-D-glucose (molar proportions 44 9 6 1 41, respectively). 

Injection of alkyl phosphates into rats raised the level of P-D-glucuronidase activity in their sera without affecting the levels of lysosomal hydrolases and cholinesterase. Dibutyl and tributyl phosphates were most and equally effective, the levels of P-D-glucuronidase activity increasing 120- and 90-fold after 1 and 2 h, respectively. The increase in enzymic activity elicited with tributyl phosphate correlated with a lowering of the enzymic activity in the liver microsomes, which appear to be the main source of the excess of P-D-glucuronidase activity in the serum. 

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Siastatin B (40), the first natural inhibitor of neuraminidase and a compound that also inhibits -D-glucuronidase, was discovered in 1974 [139]. Two total syntheses of this compound have been published to date [140,141]. Due to the fact that recent studies have shown that human tumours are associated with... 

Fishman s point of view was based largely on the following observations. (a) Glucuronogenic substances, such as borneol, increase the /3-D-glucuronidase activity of the liver, kidney, and spleen, (b) The conjugation of phenol by rat-liver slices, inhibited by monoiodoacetate, is... 

Levvy193 were unable to observe conjugation of o-aminophenol with D-glu-curonic acid in the presence of a /3-D-glucuronidase preparation. No conjugation was found in a similar system, using /3-D-glucuronic acid 1-phosphate.22 194... 

Harris and Cohen204 found that ovariectomy lowers the uterine activity of /3-D-glucuronidase but does not affect the activity of vagina, liver, kidney, and spleen of mice. Estrone restores the uterine-enzyme activity and increases mammary-gland levels, but does not affect the other organs. They found that the phosphatase levels more closely paralleled tissue growth than did /3-glucuronidase. 

In experiments on patients with breast cancer, it was found that up to a two-fold increase in serum /3-D-glucuronidase followed surgery, pregnancy, prolonged estrogen or cortisone therapy, etc.206 The /3-D-glucu-ronidase rise was usually accompanied by a fall in serum esterase, in both animal and human experiments. A rise in urinary ketosteroid excretion usually paralleled the changes, in man. 

It would seem that, at present, the data demand the interpretation that /3-D-glucuronidase is a purely hydrolytic enzyme that it does not catalyze glucosiduronic acid synthesis that it may, in some cases, be associated with rapid, cell division, and that its apparent relationship to estrogen and to cancer is probably on this basis and, finally, that, although its adaptive characteristics have not been disproved, they are unlikely to exist. If they should exist, the basis is most probably the hydrolytic function. It would seem that /3-D-glucuronidase bears the same relationship to glucuronic conjugates that phenolsulfatase bears to ester sulfates. 

A large number of substances have been shown to have the property of inhibiting /3-D-glucuronidase. The most potent of all, according to Lewy,68 is D-glucaro-1,4-lactone (XXXVI), whose structure is shown below for comparison with that of a /3-D-glucosiduronic acid (XXXVII). This in-... 

From the practical point of view, the use of /3-D-glucuronidase, both animal214 and bacterial,216 as a tool in steroid research has been highly productive of improved methods for determinations of urinary 17-keto-steroid and cortin and for isolating new steroids. 

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