Diessel Duan

Haijun Duan came to Auburn University in the Fall of 2008.  He joined the Goodwin laboratory in January 2009. Haijun is known around the Department and the lab as "Diessel". Diessel contributed to a number of aspects of our work on KatG. He evaluated a series of intrasubunit interdomain interactions and their role in maintaining active site structure and function.  Diessel also made a critical contribution to our understanding of the part that peroxidatic electron donors play in stimulating the catalase activity of KatG.  By generating a series of E. coli mutants lacking the peroxide defensive systems katE, katG, and ahpCF (singly and in combination) and using a completmentation strategy with MtKatG and catalase-inactive variants thereof, Diessel was able to show that the peroxidatic electron donor stimulatory effect protected intact cells from the toxic effects of hydrogen peroxide. Most interestingly, katE katG double mutant and katE katG ahpCF triple mutants were protected from hydrogen peroxide-dependent toxicity when complemented with the Mt katG gene, and this protective effect was stimulated by the peroxidatic electron donors.  However, complentation with the Y229F katG gene afforded no protection from hydrogen peroxide toxicity in the presence or absence of peroxidatic electron donor. On November 10, 2014, Diessel defended his dissertation entitled KatG as a Defense Against Hydrogen Peroxide Toxicity: From a Redundant C-terminal Domain to the Paradoxical Synergy of Two Mutually Antagonistic Activities.  Dr. Haijun Duan is now a postdoctoral associate in the laboratory of Professor Anne-Frances Miller at the University of Kentucky.

Duan, H., Suh, S.-J., and Goodwin, D. C. 2013. Mechanism for stimulation of bacterial defenses against H2O2 by peroxidatic electron donors.  99th Annual Southeastern Branch of American Society of Microbiology Meeting (SEBASM), Auburn University, AL .

Duan, H., and Goodwin, D.  2011.  Essential role of distant interdomain interactions in H2O2 decomposition by catalase-peroxidases.  18th Annual Meeting of the Society for Free Radical Biology and Medicine, Atlanta, GA.