Philippe Urban

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The dehydroepiandrosterone (DHEA) 7alpha-hydroxylation in humans takes place in the liver, skin, and brain. These organs are targets for the glucocorticoid hormones where 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) activates cortisone through its reduction into cortisol. The putative interference of 7alpha-hydroxy-DHEA with the(More)
The ability of four mammalian cytochromes P450 (CYP) of the CYP1A subfamily, human and mouse CYP1A1s and human and rabbit CYP1A2s, to metabolize a series of steroids and related compounds was investigated using high throughput approaches. Oxidation rates and metabolite patterns for 16 steroid substrates and for 20 polycyclic aromatic hydrocarbon (PAH)(More)
Rat brain cysteine sulfinate decarboxylase (EC, a key enzyme in taurine biosynthesis, has been separated from glutamate decarboxylase (EC associated activity and purified to apparent homogeneity. The monomeric enzyme of molecular weight 70,000 +/- 2,000 exhibits half-maximal velocity with 90 +/- 40 ? M cysteine sulfinate or approximately(More)
The promiscuity of a collection of enzymes consisting of 31 wild-type and synthetic variants of CYP1A enzymes was evaluated using a series of 14 steroids and 2 steroid-like chemicals, namely, nootkatone, a terpenoid, and mifepristone, a drug. For each enzyme-substrate couple, the initial steady-state velocity of metabolite formation was determined at a(More)