Elizabeth Ndontsa

Elizabeth came to Auburn University in the Fall of 2008, and she joined the Goodwin laboratory in January 2009.  Following up on an observation made by Robert Moore, Elizabeth characterized a heretofore unanticipated interplay between the catalase and peroxidase activities of KatG.  That is, many compounds which can act as peroxidatic electron donors serve to dramatically stimulate catalase activity.  The effect was particularly prominent in KatG from Mycobacterium tuberculosis.  Elizabeth made a thorough investigation of the phenomenon by steady-state and enzyme-monitored rapid reaction techniques. As one can clearly observe below, her work in this area has spawned and underpinned the efforts of numerous graduate and undergraduate students who have come after her.  Elizabeth's work represented our first extensive use of M. tuberculosis KatG, and as such, Elizabeth was the first in our group to successfully produce MtKatG variants. Because it is not possible to reconsititute this KatG with heme after expression, Elizabeth used our own pHPEX system for expression of substantial quantities of holo-MtKatG. On May 5, 2013, Elizabeth defended her dissertation entitled Synergy not Antagonism in Antioxidant Defenses: The Unanticipated Effect of Electron Donors on Catalase-Peroxidase Function. Dr. Ndontsa is now working in industry with Aduro Biotech in Berkeley, CA.

Publications, Presentations, and Abstracts:

Njuma, O. J., Davis, I., Ndontsa, E. N., Krewall, J. R., Liu, A., and Goodwin, D. C. 2017. Mutual synergy between catalase and peroxidase activities of the bifunctional enzyme KatG is facilitated by electron-hole hopping within the enzyme. J. Biol. Chem. 292, 18408 - 18421.

Njuma, O. J., Davis, I., Ndontsa, E. N., Liu, A., and Goodwin, D. C. 2015. Proximal tryptophan and arginine switch participation in catalase-peroxidase inactivation. Gordon Research Conference: Enzymes, Coenzymes, and Metabolic Pathways, Waterville Valley, NH (7/13/15 -7/14/15)


Njuma, O. J., Davis, I., Ndontsa, E. N., Liu, A., and Goodwin, D. C. 2015. Participation of the proximal tryptophan as a potential conduit for catalase-peroxidase inactivation. 6th Annual Southeast Enzymes Conference, Georgia State University, Atlanta, GA (4/11/15).

Njuma, O. J., Ndontsa, E. N., and Goodwin D. C. 2014. Catalase in peroxidase clothing: Interdependent cooperation of two cofactors in the catalytic versatility of KatG. Arch. Biochem. Biophys. 544, 27 39.


Njuma, O. J., Ndontsa, E. D., and Goodwin, D. C. 2014. Evaluating the role of peroxidatic reducing substrates in an unusual catalase activity of catalase-peroxidases. 2014 Symposium, The Protein Society, San Diego, CA. (7/27/14)

Njuma, O. J., Ndontsa, E. D., and Goodwin, D. C. 2014. Synergistic effect of peroxidatic electron donors on the catalase activity of Catalase-Peroxidase. 5th Annual Southeast Enzymes Conference, Georgia State University, Atlanta, GA. (4/5/14)

Njuma, O. J., Ndontsa, E. N. and Goodwin, D. C. 2014. Evaluating the role of electron donors in a novel mechanism of H2O2 decomposition by Catalase-Peroxidase. 91st  Alabama Academy of Science Meeting (AAS), Auburn University, AL (3/13/14)

McCurdy, E., Ndontsa, E., and Goodwin, D. 2014. W438 and the Diminished Necessity for Peroxidatic Rescue of KatG Catalatic Turnover. 34th Annual Undergraduate Research Conference, University of Memphis, Memphis, TN.

 

McCurdy, E., Ndontsa, E. N., and Goodwin, D. C. 2013. An Investigation of W438 as a Potential Route for Off-Pathway Electron Transfer and Its Relationship to the Bifunctional Activity of Catalase-Peroxidase.  Southeast Regional Meeting of the American Chemical Society (SERMACS), Atlanta, GA. (Won first prize for undergraduate poster session).

Njuma, O. J., Ndontsa, E. N., and Goodwin, D. C. 2013. Rescue of catalase-inactive intermediates of KatG by peroxidatic electron donors. Southeast Regional Meeting of the American Chemical Society (SERMACS), Atlanta, GA

 

Njuma, O. J., Ndontsa, E. N and Goodwin, D.C. 2013. KatG: Improvisation of novel peroxide decomposition mechanisms. 99th Annual Southeastern Branch of  American Society of  Microbiology Meeting (SEBASM), Auburn University, AL

Njuma, O. J., Ndontsa, E. N., and Goodwin, D. C. 2013. Electron donors to the rescue: Evaluating a novel mechanism of hydrogen peroxide decomposition by catalase-peroxidases. National Meeting of the National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCCHE), Indianapolis, IN

 

Njuma, O. J., Ndontsa, E. N., and Goodwin, D. C. 2013. Surprising role of peroxidatic electron donors in the catalase activity of catalase-peroxidase. Diversity Awareness Symposium, Tuscaloosa, AL.  (Award-winning poster)

 

Njuma, O. J., Ndontsa, E. N., and Goodwin, D. C. 2013. Surprising role of peroxidatic electron donors in the catalase activity of Catalase-Peroxidase. Fourth Southeast Enzymes Conference, Atlanta, GA.

 

Ndontsa, E.N., Moore, R.L., and Goodwin, D.C.  2012.  Stimulation of KatG catalase activity by peroxidatic electron donors Arch. Biochem. Biophys. 105, 215 - 222.

Ndontsa, E. N., and Goodwin D. C. 2012. Multiple mechanisms for KatG catalase activity: Electron donors, pH, and an arginine "switch. 2012 Annual Meeting of the Southeast Region of the American Chemical Society, Raleigh, NC.

 

Ndontsa, E. N., and Goodwin, D. C. 2012. Role of Arg 418 switch in electron-donor-enhanced catalase activity of M. tuberculosis catalase-peroxidase (KatG).  Annual National Meeting NOBCChE, Washington, D.C.

 

Ndontsa, E. N., and Goodwin, D. C. 2012. Role of Arg 418 switch in electron-donor-enhanced catalase activity of M. tuberculosis catalase-peroxidase (KatG).  Third Southeast Enzymes Conference, Atlanta, GA.

Ndontsa, E. N., and Goodwin, D. C. 2011.  An improvised mechanism for H2O2 disproportionation based on an old enzyme scaffold.  18th Annual Meeting of the Society for Free Radical Biology and Medicine, Atlanta, GA.

Ndontsa, E. N., and Goodwin, D. C. 2011.  An improvised mechanism for H2O2 disproportionation based on an old enzyme scaffold.  Southeast/Southwest Regional Meeting, National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChe), Auburn, AL (1st Place award winning presentation)

Ndontsa, E., and Goodwin, D. C.  2011.  Stimulation of catalase activity of catalase-peroxidases by peroxidase reducing substrates:  New functions from old scaffolds.  Second Southeast Enzymes Conference, Atlanta, GA.