Gregory M. Raner
My research is mostly centered around a single class of enzymes, the cytochrome P450s. These enzymes are present in nearly all life forms ranging from simple one-celled organisms to humans, and catalyze oxidative or reductive reactions in support of a variety of cellular functions. In humans, one of the primary functions is the removal of foreign chemicals (including many pharmaceutical agents) from the body. The enzymes use molecular oxygen and the cellular reducing agent NADPH to oxidize the foreign compounds which usually facilitates their elimination by a supporting class of enzymes called Phase II enzymes, which may also contribute to cellular anti-oxidant responses.
One of my research goals is to understand the chemistry behind cytochrome P450- catalyzed de-fluorination of fluorinated aromatic and aliphatic substrates using a combination of site-directed mutagenesis and a variety of kinetic and spectroscopic methods. These de-fluorination reactions are of tremendous significance given the success of new fluorinated chemical species in the pharmaceutical and agrochemical industries.
A second goal is to study potential interactions between natural products and human Phase I and Phase II enzymes: More specifically, inhibitory interactions between chemical constituents of essential oils or plant extracts and cytochrome P450 enzymes may give rise to beneficial or harmful effects in humans, and an understanding of these interactions will lead to safer and more effective uses for these products. In addition, constituents of certain natural products appear to induce anti-oxidant gene expression in human liver cells, supporting a potential protective effect in humans. We are currently exploring the Acai Berry for its potential to interact with human cytochrome p450 enzymes and cellular antioxidant systems .
- Raner, G.M., A.D.N. Vaz, and M.J. Coon.Metabolism of All-trans, 9-cis, and 13-cis Isomers of Retinal by Purified Isozymes of Microsomal Cytochrome P450 and Mechanism-based Inhibition of Retinoid Oxidation by Citral.Mol. Pharmacol. 49:515-522 (1996).
- Vaz, A.D.N., S.J. Pernecky, G.M. Raner, and M.J. Coon. Peroxo-iron and Oxenoid-iron Species as Alternative Oxygenating Agents in Cytochrome P450-catalyzed Reactions: Switching by Threonine-302 to Alanine Mutagenesis of Cytochrome P450 2B4. Proc. Natl. Acad. Sci. U.S.A.93:4644-4648 (1996).
- Guengerich, F.P., A.D.N. Vaz, G.M. Raner, S.J. Pernecky, and M.J. Coon.Evidence for a Role of a Perferryl-Oxygen Complex, FeO3+, in the N-Oxygenation of Amines by Cytochrome P450 Enzymes.Mol. Pharmacol. 51:147-151 (1997).
- Raner, G.M., E.W. Chiang, A.D.N. Vaz, and M.J. Coon.Mechanism-Based Inactivation of Cytochrome P450 2B4 by Aldehydes:Relationship to aldehyde Deformylation via a Peroxyhemiacetal Intermediate. Biochemistry 36:4895-4902 (1997).
- Williams, S.K.R., G.M. Raner, W.R. Ellis, Jr., and J.C. Giddings.Separation of Protein Inclusion Bodies from Escherichia coliLysates Using Sedimentation Field-Flow Fractionation.J. Micro. Sep. 9:233-239 (1997).
- Raner, G.M., L.J. Martins, and W.R. Ellis, Jr. Functional Role of Leucine-103 in Myohemerythrin. Biochemistry 36:7037-7043 (1997).
- Zhang, Q.-Y., Raner, G., Ding, X., Dunbar, D., Coon, M.J., and Kiminsky, L.S.Characterization of CYP2J4:Expression in Rat Small Intestine and Role in Retinoic Acid Biotransformation from Retinal.Arch. Biochem. Biophys. 353:257-264 (1998).
- Shank-Retzlaff, M.L., G.M. Raner, M.J. Coon, and S.G. Sligar.The Membrane Topology of Cytochrome P450 2B4 in Langmuir-Blodgett Monolayers. Arch Biochem. Biophys. 359: 82-88 (1998).
- Kuo, C.-L., G.M. Raner, A.D.N. Vaz, and M.J. Coon.Discrete Species of Activated Oxygen Yield Different Cytochrome P450 Heme Adducts from Aldehydes.Biochemistry 38:10511-10518 (1999).
- Lloyd, C.R., G.M. Raner, A. Moser, E.M. Eyring, and W.R. Ellis, Jr.Oxymyohemerythrin:Discriminating Between O2 Release and Autoxidation.J. Inorg. Biochem. 81:293-300 (2000).
- Raner, G.M. A.J. Hatchell, P.E. Morton, D.P. Ballou, and M.J. Coon. Stopped-Flow Spectrophotometric Analysis of Intermediates in the Peroxo-Dependent Inactivation of Cytochrome P450 by Aldehydes. J. Inorg. Biochem. 81: 153-160 (2000).
- Raner, G.M., A.Q. Muir, C. Lowry and B.A. Davis. Farnesol as an Inhibitor and a Substrate for Rabbit Liver Microsomal P450 Enzymes. Biochem. Biophys. Res. Commun. 293, 1-6 (2002).
- Raner, G.M., J.A. Hatchell, M.U. Dixon, T. Joy, A.E. Haddy, and E.R. Johnston. Regioselective Peroxo-Dependent Heme Alkylation in P450BM3-F87G by Aromatic Aldehydes: Effects of Alkylation on Catalysis. Biochemistry 41, 9601-9610 (2002).
- Dixon, M.U., O. Omoseebi, A.A. Lawson, J. Bao, J.P. Handler, S.A. Brown, L. King, A. Mortenson, and G.M. Raner, Oxidation of 4-nitrophenol and 4-nitrocatechol by wild-type and mutant P450BM3 enzymes. J. Undergrad. Chem. Res. 4, 149-155 (2002).
- Yang, S.-P., T. Medling, and G.M. Raner. Cytochrome P450 Expression and Activities in the Rat, Rabbit and Bovine Tongue. Comp. Biochem. Physiol. C. 136, 297-308 (2003).
- Yang, S.-P. and Raner, G.M. Cytochrome P450 Expression, Induction and Activities in Human Tongue Cells and their Modulation by Green Tea Extract, Toxicol. Appl. Pharmacol. 202, 140-150 (2005).
- Perera, R., M. Sono, G.M. Raner, and J.H. Dawson. Subzero-temperature stabilization and spectroscopic characterization of homogeneous oxyferrous complexes of the cytochrome P450BM3 (CYP102) oxygenase domain and holoenzyme. Biochem. Biophys. Res. Commun. (2005).
- Cech, N. B., Tutor K. , Doty, B. , Spellman, K. , & Sasagawa, M. , Gregory M. Raner Cynthia A. Wenner. Liver Enzyme-Mediated Oxidation of Echinacea purpurea Alkylamides: Production of Novel Metabolites and Changes in Immunomodulatory Activity.CHE Planta Medica, 72, 1372-1377 (2006).
- Raner, G. M., Thompson J. I., Haddy, A. , Tangham, V. , & Bynum, N. , Reddy Ramachandra David P. Ballou John H. Dawson, Spectroscopic investigations of intermediates in the reaction of cytochrome P450(BM3)-F87G with surrogate oxygen atom donors. J. Inorg. Biochem. 100 (12), 2045-2053 (2006).
- Osborne, R. L., Raner, G. M., Hager, L. P., & Dawson, J. H. C. fumago chloroperoxidase is also a dehaloperoxidase: oxidative dehalogenation of halophenols. J. Amer. Chem. Soc., 128 (4), 1036-1037 (2006).
- Yang, S., Wilson, K. , Kawa, A. , & Raner, G. M. Effects of Green Tea Extracts on Gene Expression in HepG2 and Cal-27 Cells.CHE Journal of Food and Chemical Toxicology, 44, 1075-1081(2006).
- Reddick, J.J., Antolak, S.A., and Raner, G.M. PksS from Bacillus subtillus is a cytochrome P450 involved in bacillaene metabolism. Biochem. Biophys. Res. Commun. 358:363-367 (2007).
- Raner, G.M., Cornelious, S., Moulick, K. Wang.Y., Mortenson, A. and Cech, N.B. Effects of herbal products and their constituents on human cytochrome P4502E1 activity. Food Chem. Toxicol. 45:2359-2365 (2007).
- Osborne, R.L., Coggins, M.K., Raner, G.M., Walla, M., Dawson, J.H. The mechanism of oxidative halophenol dehalogenation by Amphitrite ornata dehaloperoxidase is initiated by H2O2 binding and involves two consecutive one-electron steps: role of ferryl intermediates. Biochemistry. 48:4231-4238 (2009).
- Bryson, D, Lim, P.L., Lawson, A., Manjunath, S., and Raner, G.M. Isotopic labeling of the heme cofactor in cytochrome P450 and other heme proteins. Biotechnol. Lett. (In Press, 2011).