Email: djosephy@uoguelph.ca

Office: SCIE 2253
Ext: 53833
Lab: SCIE 2205
Ext: 54590

Profile

Dr. David Josephy’s research interests are in the field of Molecular Toxicology, including trace analysis of environmental carcinogens; mechanistic studies of enzymes that catalyze the metabolism of drugs and toxicants; and the development of bacterial mutagenicity assays. Dr. Josephy teaches courses in Biochemistry (including the Introductory Biochemistry course BIOC*2580) and Toxicology. He is the co-author of the textbook "Molecular Toxicology" (Oxford University Press); the second edition was published in 2006. Prof. Josephy is also a member of the executive of the University of Guelph Faculty Association.

Education

B.Sc. Toronto
Ph.D. University of British Columbia

Research

Aromatic amines are a long-standing interest in my laboratory; this class of chemicals includes important industrial chemicals and many pharmaceuticals. The related heterocyclic amines are potent mutagens formed during the cooking of protein-rich foods, such as grilled meat and fish. My research program focuses on enzymes of xenobiotic metabolism, especially the human cytochromes P450, N-acetyltransferase (NAT), and Theta-class glutathione transferase (GST) enzymes. We want to understand their mechanisms of catalytic activity and substrate specificity. "SNPs" (single-nucleotide polymorphisms) are genetic variants that have been discovered in the human population; we are characterizing the functional effects of SNPs in xenobiotic metabolism enzymes. We are also analyzing these enzymes by high-throughput screening of variants generated by random mutagenesis.

Please see Research Projects for further information.

Selected Publications

Josephy, P.D., Kent, M., Mannervik, B., Single-nucleotide polymorphic variants of human glutathione transferase T1-1 differ in stability and functional properties, Archives of Biochemistry and Biophysics 490: 24-29, 2009

Zenser, T.V., Lakshmi, V.M., Schut, H.A., Zhou, H.J., Josephy, P.D., Activation of aminoimidazole carcinogens by nitrosation: mutagenicity and nucleotide adducts, Mutation Research. 673: M109-115, 2009

Josephy, P.D., Weadge, J.J., Meissner, J., Ng, F., Ames test evaluation of two commercially available zero-valent nickel compounds, Mutation Research 654:64-68, 2008

Scott, K.A., Turesky, R.J., Wainman, B.C. Josephy, P.D., HPLC/electrospray ionization mass spectrometric analysis of the heterocyclic aromatic amine carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in human milk, Chemical Research in Toxicology 20: 88-94, 2007.

Josephy, P.D., Taylor, P.L., Vervaet, G., and Mannervik, B., Screening and characterization of variant Theta class glutathione transferases catalyzing the activation of ethylene dibromide to a mutagen, Environmental and Molecular Mutagenesis 47: 657-665, 2006.

Complete list

Teaching

Introductory Biochemistry - BIOC 2580

Grad Students

Bazinet, Rob (M.Sc.)
Scott, Kara (Ph.D.)

Josephy Laboratory Home Page