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
then spent four years with Aduro Biotech in Berkeley, CA, rising to
a Senior Scientist position. She is currently with Gilead Sciences
in Foster City, CA, where she is a Senior Project Manager.
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.
91stAlabama
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 fortheProfessional 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.