Dr. Gretchen L. Anderson
Professor of Biochemistry
Department of Chemistry
Indiana University South Bend
1700 Mishawaka Ave
South Bend, IN 46634-7111
574-520-4820
fax: 574-520-5589
ganderso@iusb.edu
Research Interests
Dr. Anderson is interested in the process by which certain strains of the bacterium, Alcaligenes faecalis, survive in otherwise lethal concentrations of arsenic. This is accomplished by the induction for the enzyme, arsenite oxidase, which transfers electrons from arsenite (AsIII) to form the less toxic arsenate (AsV). The work with arsenite oxidase has focused in the last several years in understanding how electrons are transferred from arsenite to the molybdopterin cofactor. Anderson and her undergraduate collaborators have shown that unlike many arsenite-inhibited proteins, cysteines are not ligands to arsenite in arsenite oxidase [McNellis, L.A. and Anderson, G.L. (1998)]. Rather, histidines are essential for activity and may serve as the ligand(s) for arsenite [McNellis, L.A. and Anderson, G.L. (1998)]. Computer modeling of arsenite in the putative binding pocket of arsenite oxidase shows two histidines appropriately aligned to serve as ligands to arsenite [Anderson, G.L. et al. (2001)]. Radiolabeling of histidines that are protected from modification in the presence of arsenite has yielded preliminary data suggesting that this is an appropriate approach to providing chemical evidence for the role of histidine [Namanja, A. and Anderson, G.L. (2002)]. Efforts are currently underway to refine these data, positively identify the radiolabeled histidines, and compare them with those predicted from modeling studies. Current plans include cloning and expressing the gene for arsenite oxidase, and testing the enzymatic effect of genetic replacement of the putative arsenite-binding histidines. An understanding of how arsenite reversibly interacts with molybdenum may eventually help avoid arsenite inhibition of molybdenum-based catalysts.
A second project addresses the role of arsenite oxidase in the respiratory metabolism of Alcaligenes faecalis. Since arsenite oxidase is part of a periplasmic electron transport chain involving at least azurin and cytochrome c [Anderson, G.L. et al. (1992)], the possibility that arsenite can serve as a source of metabolic energy source was explored [Anderson, G.L., et al. (2003)]. The conversion of arsenite to arsenate by A. faecalis may complement and facilitate current methodologies for removing arsenic from well water.
Anderson has also developed several laboratory exercises for use in lab courses [e.g. McNellis, L.A. and Anderson, G.L. (1998)], and continues to explore new approaches in classroom teaching [Anderson, G.L. and Heck, M.L. (2005), Anderson, G.L. (2004), Anderson, G.L. (1998)].
References:
Anderson, G.L. and Heck, M.L. (2005) “Theme-based tests: teaching in context” Biochemistry and Molecular Biology Education 33, 8-14
Anderson, G.L. (2004) “Demonstration of Enantiomer Specificity of Proteins and Drugs” J. Chem. Ed. 81, 971
Anderson, G.L. (2004) “Something Old, Something New: A Twist on the Traditional Term Paper” Quick Hits for New Faculty, Cordell, R., Lucal, B., Morgan, R. (ed.) Indiana University Press, Bloomington, IN.
Anderson, G.L., Love, M., Zeider, B.K. (2003) “Metabolic Energy from Arsenite Oxidation in Alcaligenes faecalis” J. de Physique 107, 49-52
Namanja, A. and Anderson, G.L. (2002) “Isolation of Peptides Containing Solvent Accessible Histidines in Arsenite Oxidase from Alcaligenes faecalis” Undergraduate Research Journal, 5, 79-83
Anderson, G.L. Ellis, P., Kuhn, P., Hille, R. (2001) “Oxidation of Arsenite by Alcaligenes faecalis” in Environmental Chemistry of Arsenic, Frankeburger, W.T., (ed.) Marcel Dekker, Inc. NY pp. 343-361
Anderson, G.L. (1998) "Chemistry Party Animals" in More Quick Hits: Successful Strategies by Award-winning Teachers, Stocking, S.H., Bender, E.T., Cookman, C.H., Petersen, V.J. and Votaw, R.B. (eds.) Indiana University Press, Indianapolis
McNellis, L.A. and Anderson, G.L. (1998) “Redox State-Dependent Inactivation of Arsenite Oxidase” J. Inorg. Biochem. 69, 253-257
McNellis, L.A. and Anderson, G.L. (1998) “Enzyme-Linked Antibodies: A Laboratory Introduction to the ELISA Assay” J. Chem. Ed. 75, 1275-1277
Anderson, G.L., Williams, J. and Hille, R. (1992) "Purification and Characterization of Arsenite Oxidase; a Molybdenum Hydroxylase" J. Biol. Chem. 267, 23674-23682
Teaching Credentials
Indiana University Herman Frederic Lieber Memorial Award for Distinguished Teaching
Indiana University South Bend Distinguished Teaching Award
Trustee's Teaching Awards
Member of FACET (Faculty Colloquium on Excellence in Teaching)
Teaching Excellence Recognition Awards
