Steroid Glucuronidase

Dray J, Dray F, Tiller F, Ulman A (1972) Hydrolysis of urine metabolites of different steroid hormons by b-glucuronidase of Escherichia coli. Ann Inst Pasteur 123 853-857... 

Using immobilized -glucuronidase reactors, estriol and estradiol glucuronides have been determined in urine by a column-switching technique (270, 271). Both glucuronides were hydrolyzed by the immobilized enzyme at pH 7. The steroid mixture was subsequently separated by gradient elution on a reversed-phase column, to be finally detected by UV absorbance at 280 nm. In this procedure, the activity of enzyme did not alter even after 150 h continuous run and exposure to a mobile phase containing 10% methanol. When a separate reversed-phase precolumn was inserted in the LC system, additional sample purification and shorter analysis time could be attained (272). 

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. 

Whether /3-glucuronidase in the organs of the cat would respond to treatment with steroid hormones and other agents in the same fashion as in other species9 is another interesting problem that arises from these experiments the enzyme in cat tissues shows the variation in activity with age (see Table I, d) first observed in mice,112 and a striking elevation in enzyme activity in cat sciatic nerve is seen after injury to the nerve.86... 

Steroids in urine Estrogens in urine, serum P-Glucuronidase/ ",so4 P-Glucuronidase/ su1fatH.se T.T.F. T.T.F. NA Dansyl chloride Deuterated isotopes LC-ESP/MS/MS [20] [8,28]... 

Adjust the urine sample to pH 5 by the addition of dilute hydrochloric acid. For each 9 volumes of urine add 1 volume of acetate buffer pH 5) containing 5000 Fishman units/ml of mixed glucuronidase/ sulphatase (from Helixpomatia), and incubate the mixture at 31 for 24 hours. Centrifuge, pour the supernatant liquid on to a column of Amberlite XAD-2 resin, wash the column with 50 ml of water, and then elute the steroids with 100 ml of ethanol. Evaporate the ethanol using a rotary film evaporator, dissolve the residue in 0.5 ml of ethanol, and add 2 ml of cyclohexane. 

In none of these studies was a reaction product actually isolated. The authors confined their work mainly to the hydrolysis of the conjugates with i8-glucuronidase and identification of the steroid residues. Consequently, it is still uncertain which glucosiduronates are formed in these experiments, and whether conjugation of the alcoholic or phenolic hydroxyl group is favored. 

Corner EDS, Leon YA, Bulbrook RD (1960) Steroid sulphatase, arylsulphatase and /S-glucuronidase in marine invertebrates. J Mar Biol Assoc UK 39 51-61 Corner EDS, Kilvington CC, O Hara SCM (1973) Qualitative studies on the metabolism of naphthalene in Maia squinado (Herbst). J Mar Biol Assoc UK 53 819-832 Corner EDS, Harris RP, Kilvington CC, O Hara SCM (1976) Petroleum compounds in the marine food web short-term experiments on the fate of naphthalene in Calanus. J Mar Biol Assoc UK 56 121-133... 

Fig. 8. Hypothesis on the controls of heme synthesis in the hepatic cell at both the transcriptional and translational levels. In the nucleus a repressor protein blocks transcription at the promoter end of the operator gene, thus preventing synthesis of the mRNA of ALA-synthetase. A 5 -H steroid removes the repression by interacting with the repressor protein. The level of the steroid is controlled by glucuronidation with UDPGA transferase which renders it inactive, and by hydrolysis with j3-glucuronidase which renders it active. In the cytoplasm heme represses the synthesis of ALA-synthetase at the translational level and thus its own synthesis. Excess heme is destroyed by heme oxygenase of the microsomes.

Stabilization of lysosomal membranes has been implicated as an Important mechanism of steroidal and non-steroidal anti-inflammatory drugs. Phenylbutazone, flufenamic acid and acetylsallcylic acid Inhibit the release of acid phosphatase and 8-glucuronidase from Isolated rat liver lysosomes incubated in buffered sucrose (pH 7. ). In acidic sucrose (pH 5), acetyl-salicylic acid enhances lysosomal enzyme release. Acetylsallcylic acid indomethacin and phenylbutazone do not stabilize rabbit liver lysosomes In vitro stabilization of isolated erythrocytes against hypotonic hemolysis and heat-induced hemolysis " by non-steroidal anti-inflammatoiy agents has been employed as a rapid, accurate screening model. The stabilizing potency apparently correlates with the clinical activities of standard anti-rheumatic drugs. 

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