Cytochrome subfamily

Compounds having the 16,17 ketal, eg, budesonide, amcinonide, fluocinonide, halcinonide, triamcinolone acetonide, and flurandrenohde, also undergo metabohsm by routes that parahel that of cortisol metabohsm. Unsymmetrical acetals such as budesonide are also metabolized by routes not available to the more metabohcahy stable symmetrical 16a,17a-isopropyhdiene-dioxysubstituted compounds (desonide, flunisohde, and triamcinolone acetonide). Isozymes within the cytochrome P450 3A subfamily are thought to catalyze the metabohsm of budesonide, resulting in formation of 16a-hydroxyprednisolone and 6P-hydroxybudesonide (19,20) (Fig. 3) in addition to the more common metabohc steps (oxidation via reduction of A, etc). 

Lewis, D. F., Lake, B. G., Ito, Y., Anzenbacher, P. Quantitative structure-activity relationships (QSARs) within cytochromes P450 2B (CYP2B) subfamily enzymes the importance of lipophilicity for binding and metabolism. Drug Metab. Drug Interact. 

CYP450 3A4, cytochrome P-450 subfamily 111A polypeptide 4 DHEA,... 

Cytochrome P450 (EC 1.14.14.1) enzymes are well known for their ability to metabolize the majority of drugs, to detoxify environmental pollutants, and to activate some classes of carcinogens [93]. The most highly expressed subfamily is CYP 3A, which includes the isoforms CYP 3A4, CYP 3A5, CYP 3A7, and CYP 3A43 [93, 94]. The most abundant isoform is CYP 3A4, which corresponds to 30% of the total P450 content in the liver and about 70% of the total P450 content in the... 

Kawashima H, Strobel HW. 1995. cDNA cloning of three new forms of rat brain cytochrome P450 belonging to the CYP4F subfamily. Biochem Biophys Res Commun 217 1137-1144. 

Stromstedt M, Warner M, Gustafsson JA. 1994. Cytochrome P450s of the 4A subfamily in the brain. J Neurochem 63 671-676. 

Wyss A, Gustafsson JA, Warner M. 1995. Cytochromes P450 of the 2D subfamily in rat brain. Mol Pharmacol 47 1148-1155. 

Cytochrome P450, subfamily IIB (phenobarbital-inducible), polypeptide 6... 

Cytochrome P450, subfamily lie (mepheny-toin 4-hydroxylase), polypeptide 19 flavo-protein-hnked monooxygenase mephenytoin 4 -hydroxylase microsomal monooxygenase xenobiotic monooxygenase... 

CYP2E1 10q24.3- Cytochrome P450, Cytochrome P450, subfamily Dexamethasone, ethanol, etoposide. Alcohohc hver CPEl CLP2E ... 

A classification system similar to that for the CYPs has been developed to characterize the UGT superfamily. There are two clinically significant hepatic UGT subfamilies (UGTIA and UGT2B) and 10 individual genes found in the liver (Tukey and Strassburg, 2000 http //www.mhc.eom//cytochromes/AJGT//index.html). 

Westlind A, Malmebo S, Johansson I, et al. Cloning and tissue distribution of a novel human cytochrome p450 of the cyp3a subfamily, cyp3a43. Biochem Biophys Res Commun 2001 281(5) 1349-13 55. 

Gorski JC, Hall SD, Jones DR, VandenBranden M, Wrighton SA. Regioselec-tive biotransformation of midazolam by members of the human cytochrome P450 3A (CYP3A) subfamily. Biochem Pharmacol 1994 47(9) 1643-1653. 

Gorski JC, Jones DR, Hamman MA, Wright on SA, Hall SD. Biotransformation of alprazolam by members of the human cytochrome P4503A subfamily. Xenobiotica 1999 29(9) 931-944. 

---