RESEARCH INTERESTS:
Structural Basis of Drug and DNA Metabolism We examine proteins and protein-DNA complexes of central importance in human disease. The primary experimental method we use is x-ray crystallography, although other biophysical, biochemical and molecular biology techniques are also employed, like high-throughput expression and purification, atomic force microscopy and NMR The group currently has two general foci: the structural basis of drug recognition and metabolism in humans, and the examination of protein-DNA complexes critical to human disease and DNA metabolism.
Drug Recognition and Metabolism. The human body must be always be alert to the presence of potentially harmful chemicals, toxins and other xenobiotic compounds. In fact, most of the drugs we take are treated as potential chemical invaders by our bodies. We are interested in unraveling how humans detect drugs at the molecular level, and how they break them down and excrete them. We have determined the crystal structure of the primary drug sensor in humans, the nuclear xenobiotic receptor PXR. The ligand-activated transcription factor controls the expression of many of the crucial drug metabolism enzymes in our bodies. We are also examining the structural basis of how human metabolize narcotics, cancer drugs, and cholesterol by unraveling the structures of the promiscuous enzymes involved. The goal of these studies is to improve the use of existing human therapeutics, and to facilitate the development of new ones.
Protein-DNA Complexes. We are examining three protein-DNA complexes involved in human disease, and in the management of DNA in cells. First, we are continuing our work on human topoisomerase I, a protein critical to all cellular processes involving DNA. Human topoisomerase I is also the sole target of the camptothecin class of potent anticancer drugs currently in wide spread clinical use. We have determined several crystal structures of topoisomerase I in complex with DNA, and are pursing the effects of common sites of DNA damage on this enzyme. Second, we are examining the Werner syndrome helicase/exonuclease. Mutations in this 1,432 amino acid bifunctional enzyme cause Werner syndrome, a rare condition characterized by a premature aging phenotype. We have shown that the exonuclease region of this protein forms a hexamer on DNA and possesses a novel endonuclease activity. Third, we are determining the crystal structure of the DNA transesterase used by bacteria to pass antibiotic resistance genes. The goal of the studies focused on protein-DNA complexes is to understand how the genetic material is manipulated, maintained and managed by cells. RECENT PUBLICATIONS:
Wierdl M, Tsurkan L, Hyatt JL, Edwards CC, Hatfield MJ, Morton CL, Houghton PJ, Danks MK, Redinbo MR, Potter PM. An improved human carboxylesterase for enzyme/prodrug therapy with CPT-11. Cancer Gene Ther. 2008 Jan 11 Xiong Y, Patana AS, Miley MJ, Zielinska AK, Bratton SM, Miller GP, Goldman A, Finel M, Redinbo MR, Radominska-Pandya A. The First Aspartic Acid of the DQxD Motif for Human UDP-Glucuronosyltransferase 1A10 Interacts with UDP-Glucuronic Acid During Catalysis. Drug Metab Dispos. 2007 Nov 29 Ortlund EA, Bridgham JT, Redinbo MR, Thornton JW. Crystal structure of an ancient protein: evolution by conformational epistasis. Science. 2007 Sep 14;317 (5844):1544-8. Epub 2007 Lujan SA, Guogas LM, Ragonese H, Matson SW, Redinbo MR. Disrupting antibiotic resistance propagation by inhibiting the conjugative DNA relaxase. Proc Natl Acad Sci U S A. 2007 Jul 24;104(30):12282-7. Epub 2007 Miley MJ, Zielinska AK, Keenan JE, Bratton SM, Radominska-Pandya A, Redinbo MR. Crystal structure of the cofactor-binding domain of the human phase II drug-metabolism enzyme UDP-glucuronosyltransferase 2B7. J Mol Biol. 2007 Jun 1;369(2):498-511. Epub 2007 Wang H, Huang H, Li H, Teotico DG, Sinz M, Baker SD, Staudinger J, Kalpana G, Redinbo MR, Mani S. Activated pregnenolone X-receptor is a target for ketoconazole and its analogs. Clin Cancer Res. 2007 Apr 15;13(8):2488-95 Fleming CD, Edwards CC, Kirby SD, Maxwell DM, Potter PM, Cerasoli DM, Redinbo MR. Crystal structures of human carboxylesterase 1 in covalent complexes with the chemical warfare agents soman and tabun. Biochemistry. 2007 May 1;46(17):5063-71. Epub 2007 Xue Y, Moore LB, Orans J, Peng L, Bencharit S, Kliewer SA, Redinbo MR. Crystal structure of the pregnane X receptor-estradiol complex provides insights into endobiotic recognition. Mol Endocrinol. 2007 May;21(5):1028-38. Epub 2007 Feb 27. Erratum in: Mol Endocrinol. 2007 Jun;21(6):1488-9 Xue Y, Chao E, Zuercher WJ, Willson TM, Collins JL, Redinbo MR. Crystal structure of the PXR-T1317 complex provides a scaffold to examine the potential for receptor antagonism. Bioorg Med Chem. 2007 Mar 1;15(5):2156-66. Epub 2006 Wadkins RM, Hyatt JL, Edwards CC, Tsurkan L, Redinbo MR, Wheelock CE, Jones PD, Hammock BD, Potter PM. Analysis of mammalian carboxylesterase inhibition by trifluoromethylketone-containing compounds. Mol Pharmacol. 2007 Mar;71(3):713-23. Epub 2006 Bencharit S, Edwards CC, Morton CL, Howard-Williams EL, Kuhn P, Potter PM, Redinbo MR. Multisite promiscuity in the processing of endogenous substrates by human carboxylesterase 1. J Mol Biol. 2006 Oct 13;363(1):201-14. Epub 2006 Noble SM, Carnahan VE, Moore LB, Luntz T, Wang H, Ittoop OR, Stimmel JB, Davis-Searles PR, Watkins RE, Wisely GB, LeCluyse E, Tripathy A, McDonnell DP, Redinbo MR. Human PXR forms a tryptophan zipper-mediated homodimer. Biochemistry. 2006 Jul 18;45(28):8579-89 Huang H, Wang H, Sinz M, Zoeckler M, Staudinger J, Redinbo MR, Teotico DG, Locker J, Kalpana GV, Mani S. Inhibition of drug metabolism by blocking the activation of nuclear receptors by ketoconazole. Oncogene. 2007 Jan 11;26(2):258-68. Epub 2006 |
Biochemistry and Biophysics - UNC School of Medicine
