Jon Friesen
Professor
B.A. 1991, Bluffton College; Ph.D. 1996, Purdue University
Research in the Friesen lab focuses on enzymes involved in biosynthesis of phosphatidylcholine. Recombinant DNA technology is utilized to produce the enzymes choline kinase and CTP:phosphocholne cytidylyltransferase. Following purification enzyme kinetic studies are conducted to elucidate the mechanism of catalysis.

Marjorie A. Jones
Professor
B.S. 1970, Central Michigan University; Ph.D. 1982, University of Texas Health Science Center
Heme metabolism and Prophyrin as therapeutic treatments: Porphyrins occur widely in nature serving biological functions such as oxygen transport (hemoglobin), photosynthesis (chlorophylls), oxygen storage (myoglobin), and energy metabolism (cytochromes). Although most organisms make their own porphyrins, one class of parasitic protozoans, called Leishmania, is not able to do so and therefore must get the prophyrins from their hosts. These parasitic protozoans infect more than 20-25 million people worldwide, and some 350 million people are at risk since they live in areas where Leishmania diseases are endemic. Such diseases can be seen as infections of skin and internal organs. There are very few good therapies being used to treat Leishmania diseases. Thus a major area of research in the Jones' Lab is the use of unique porphyrin derivatives as potential cytotoxic agents for Leishmaia diseases. Monitoring changes in cell shape, size, and motility as well as analysis for cell viability are done following addition of derivatives at various concentrations. We also are working to determine the mechanism of cytotoxicity of the effective porphyrin derivatives. The long term goal is to develop these derivatives as selective pharmaceutical drugs to treat human Leishmania diseases.

Steven J. Peters
Assistant Professor
B.S. 1989 and M.S. 1990, Illinois State University; Ph.D. 1997, Indiana University
Physical Biochemistry
Research interests in the Peters group involve the chemistry of free radicals and radical anions, particularly those that are important to polymeric chemistry and biochemistry. We employ magnetic resonance techniques to explore the chemistry of these systems. My students and I have been looking at the electron-initiated cycloaddition of isocyanates that result in the formation of stable isocyanurate anion radicals; both isocyanates and isocyanurates are important in polyurethane chemistry. We are exploring the reduction of a variety of aryl substituted isocyanates. My group is also interested in the reactivity of phenoxyl radicals with nitrogen oxide free radicals, both of which are important in many environmental and biological processes. We have just finished investigating the rearrangement mechanism of a sterically hindered nitrocyclohexadienone under anaerobic conditions. Notably we discovered that a key step in this mechanism is the release of the free radical nitric oxide, which is an important biological messenger in numerous living organisms.

Sharon L. Weldon
Assistant Professor
A.S. 1976, Mesa College; B.S. 1978, Colorado State University; M.S. 1980, University of California, San Diego; Ph.D. 1984, University of California, San Diego
The Weldon lab studies two structurally distinct forms of phosphoenolpyruvate carboxykinase found in either the cytosol (PEPCK-C) or mitochondria (PEPCK-M). Although the two forms are 40 percent nonidentical in amino acid makeup, they are similar in structure and catalysis. The lab uses site-directed mutagenesis of cDNAs for both isozymes in order to determine effects of specific amino acids on catalytic function. Additional studies investigate the influence of structure on protein and mRNA stability of these PEPCK isozymes. The short half-life and hormonal control of PEPCK-C suggests that there are labile regions in either the mRNA or protein.