Bilirubin glucuronoside glucuronosyltransferase (EC 2.4.1.95) converts bilirubin monoglucuronide to bilirubin diglucuronide and is concentrated in plasma membrane-enriched fractions of rat liver homogenates. The enzyme was purified 2,000-fold to homogeneity from rat liver. The p1 of the enzyme is 7.9 + 0.2. The enzyme has a molecular weight of 160,000 and is an oligomer of 28,000 dalton subunit...

Bilirubin pigments were studied in the bile of 20 normal adults, 25 patients with Gilbert's syndrome, 9 children with Crigler-Najjar disease, and 6 patients with hemolysis, to determine how a deficiency of hepatic bilirubin UDP-glucuronosyltransferase would affect the end products of bilirubin biotransformation. In the bile from patients with Gilbert's syndrome, a striking increase was found in...

1. Hepatic bilirubin UDP-glucuronosyl transferase activity in heterozygous Gunn rats (Jj) was only two-thirds of that in the parent Wistar rats (JJ). The former excreted only 30% of their bilirubin conjugates into bile as diglucuronide in contrast to 48% in the Wistar rats. As similar changes have been observed in Gilbert's syndrome, heterozygous Gunn rats can be used as a model for this disord...

Dietary antioxidants protect laboratory animals against the induction of tumors by a variety of chemical carcinogens. Among possible media nisms, protection against chemical cardnogenesis could be mediated via antioxidant-dependent induction of detoxifying enzymes. Therefore, we investigated the effects of two commonly used food preservatives, butyl ated hydroxyanisole (BHA) and butylated hydro...

Bilirubin glucuronoside glucuronosyltransferase (EC 2.4.1.95) converts bilirubin monoglucuronide to bilirubin diglucuronide and is concentrated in plasma membrane-enriched fractions of rat liver homogenates. The enzyme was purified 2,000-fold to homogeneity from rat liver. The pI of the enzyme is 7.9 +/- 0.2. The enzyme has a molecular weight of 160,000 and is an oligomer of 28,000 dalton subun...

Qualitative and quantitative differences of purified hepatic 3 alpha-hydroxysteroid UDP-glucuronosyltransferase were investigated in Wistar and Sprague-Dawley rats. Individual differences in the glucuronidation rate of androsterone and chenodeoxycholic acid were observed in hepatic microsomal fractions from Wistar but not Sprague-Dawley rats. No individual variation was observed in the glucuron...

The biochemical and functional properties of p-glucuronidase and j?-galactosidase, isolated and partially purified from the sponge Geodia cydonium, were studied. The two glycosidases are not only localized in the cytoplasm but are also associated at a high activity with the cell membrane. The aggregation receptor, a low molecular weight cell surface-bound glycoprotein, is deglucuronylated by th...

Because of their high cost, lysolecithins are generally not considered useful detergents for the purification of membrane-bound enzymes. Therefore, we have synthesized a structural analog of lysolecithin with similar physical properties for which synthesis is straightforward. This analog is 1-palmitoylpropanediol-3-phosphocholine. To compare the efficacy of the two detergents for the purificati...

Contribution of translocon peptide channels to the permeation of low molecular mass anions was investigated in rat liver microsomes. Puromycin, which purges translocon pores of nascent polypeptides, creating additional empty pores, raised the microsomal uptake of radiolabeled UDP-glucuronic acid, while it did not increase the uptake of glucose-6-phosphate or glutathione. The role of translocon ...