Oklahoma State University
Gilbert H. John, Ph.D.
FAX (405) 744-6790
307 Life Science East
Stillwater, OK 74078
My broad research interest is to study the structure and function of azoreductase, an oxidoreductase, in Enterococus faecium, Clostridium perfringens, and Pseudomonas aeruginosa. These bacteria are potential pathogens in humans. We have rescued the genes and characterized the proteins for azoreductase activity in the above mentioned bacteria. Our current interest is to determine if these proteins contain additional function that include quinone reductae and nitroreductase thereby making azoreductase multi-functional. This multi-functional role may provide a mechanism for bacterial survival which can support pathogenicity.
Positions and Honors
Teaching Assistant for Microbiology 200, Colorado State University, Fall, 1989
Postdoctoral Fellow with L.W. Mayer, Centers for Disease Control, Division of Molecular Biology, Lyme Disease Section, Fort Collins, CO, June 1990 to May 1992.
Summer Postdoctoral Fellowship with R.P. Ellis, Colorado State University, Department of Microbiology, Fort Collins, CO, June 1992 to August 1992.
Adjunct Faculty, Microbiology Instructor, Front Range Community College, Fort Collins, CO, June 1992 to August 1992
Assistant Research Scientist with J.R. Halpert, University of Arizona, Department of Pharmacology and Toxicology, Tucson, AZ, August 1992 to October 1995
Associate Adjunct Faculty, Microbiology Instructor, Pima Community College, Tucson, AZ, January 1994 to May 1995
Assistant Professor, Department of Microbiology and Molecular Genetics, Stillwater, OK, October 1995 to 2001
Associate Professor, Department of Microbiology and Molecular Genetics, Stillwater, OK, July 2001-presen
SLOAN Ph.D. Program Director, OSU, 2002-present
Director NABS, NSF, 2009-present
Faculty Council Research Committee Chair, 2013-15
NSF Program Director (EHR-DGE), 2012-13.
Selected peer-reviewed publications (in chronological order)
1. John, G.H., J.A. Hasler, Y. He, and J.R. Halpert. E. coli Expression and Characterization of Cytochromes P450 2B11, 2B1, and 2B5. Arch. Biochem. Biophys. 314:367-375 (1994)
2. Hasler, J.A., G.R. Harlow, G.D. Szklarz, G.H. John, K.M. Kedzie, V.L. Burnett, Y. He, L.S. Kaminsky and J.R. Halpert. Site-directed Mutagenesis of Putative Substrate Recognition Sites in Cytochrome P450 2B11. Importance of Amino Acid Residues 114, 290, and 363 for Substrate Specificity. Mol. Pharmacol. 46:338-345 (1994)
3. Born, S.L., G.H. John, G.R. Harlow and J.R. Halpert. Characterization of the Progesterone 21hydroxylase Activity of Cytochrome P450 PBD-2/P450 2B11 Through Reconstitution, Heterologous Expression, and Site-directed Mutagenesis. Drug Metab. Dispos., 23:702-707 (1994)
4. John, G.H., R. Smith, K.J. Abraham, and R.P. Ellis. Identification and grouping of Dichelobacter nodosus, using PCR and sequence analysis. Molec. Cell. Probes, 13:61-65 (1999)
5. Udeh, P., ,Venstra, J, Abraham, K.J., and John, G.H.. Quantitative polymerase chain (QPCR) reaction using the MIMIC approach to estimate Cryptosporidium parvum oocysts, an intestinal pathogen, in municipal water treatment sludge samples. Molecular and Cellular Probes, 14:121-126 (2000)
6. John, G.H., Abraham, K.J., Goodfox-Jones, J., Keith, R., and Walls, S. Identification of cytochrome P450-like protein in the human intestinal microflora, Eubacterium aerofaciens. Microbial Ecology in Health and Disease, 13:3-8 (2001)
7. John, G.H., and Keith, R. Induction of a stress protein in Eubacterium biforme by the surfactant CTAB, Microbial Ecology in Health and Disease, 13:229-233 (2001)
8. Tucker, K., Jacobs, D., Manjarrez, J., and John, G.H. The metabolism of phenobarbital, a drug used for epilepsy, by intestinal microflora, Bifidobacterium adolescentis and Bifidobacterium bifidum. Microbial Ecology in Health and Disease, 18:32-37 (2006)
9. Abraham, K.J. and John, G.H. Development of a Classification Scheme Using a Secondary and Tertiary Amino Analysis of Azoreductase Gene. Scientific Journals International, (J. Med. Biolog. Sci.), Vol. 1: Issue 1, 1-5 (2007)
10. Punj, S. and John, G.H. Physiological characterization of Enterococcus faecalis during azoreductase activity, Microbial Ecology in Health and Disease, 20:65-73 (2008)
11. Sumit Punj and Gilbert H. John. Purification and Identification of an FMN-dependent NAD(P)H Azoreductase from Enterococcus faecalis, Curr. Issues Mol. Biol. 11:59-66 (2009)
12. MacWana, S. Punj, S., Cooper, J., Schwenk, E. and John, G.H. Identification and Isolation of an Azoreductase from E. faecium. Curr. Issues Mol. Biol. 12:43-48 (2009)
13. Morrison, J.M., Wright,C.M., and John, G.H. Identification, Isolation, and Charactererization of a Novel Azoreductase from Clostridium perfringens. Anaerobe, 18(2), 229-34 (2012)
14. Morrison, J.M. and John, G.H. The non-enzymatic reduction of azo dyes by flavin and nicotinamide cofactors under varying conditions. Anaerobe, 23:87-96 (2013)
15. Morrison, J.M., Dai, S.; Taylor, A.; Wilkerson, M.; John, G. and Xie, A. Structure and stability of an azoreductase with an FAD cofactor from the strict anaerobe Clostridium perfringens. Protein Peptide Letters. 21 (2014) 523-534 (2013)