Ph.D. in physiology and pharmacology at Duke University

Classes - Animal Physiology, Neuroscience Seminar, Integrated Chemistry & Biology - Cells, Mathematics of Biology lab program, Writing in India, Advanced Cell Biology

Research - My research centers on how organisms adapt to their environments at the molecular level. My particular strength is in the properties of biological membrane and how these vary with temperature, diet or exogenous compounds (natural or exotic). I am also interested in characterizing enzyme isoforms as a function of temperature—looking for changes in fundamental parameters such as turnover number and substrate binding affinity. Finally, I am doing some “literature” based research to write interesting learning modules that involve small “systems” (systems biology) of signal molecules and receptors or metabolic pathways as part of building a repertoire of math bio exercise.

For membranes, I am particularly interested in why we have so many different types of lipids and why they are distributed in very specific ways in the cell. Our specific research ranges from fusion among membranes to reconstitution of membrane components using detergents. I am particularly interested in how exogenous compounds such as the plant phytoalexin dihydrowyrone or the protein annexin alters lipid packing and fluidity. Moreover, when these molecules insert into or bind to membrane surfaces, do the changes they induce actually affect function? Are the membranes more or less likely to fuse? Will proteins such as integral H+-ATPases or peripheral phospholipases be affected (kinetics)?

We are just diving into the world biological enzyme activity with a series of questions about how the critically important metabolic pathway enzymes function in animals experiencing temperature extremes. For example, some insects emerge in winter!!! How do they manage? Do they make more of each enzyme or do they have a version of each (e.g., lactate dehydrogenase) that can work at really cold temperatures. Are there organisms that are working at the upper limits of the enzymes they have? How will global warming affect them?

If you are interested in “systems biology” and want to do a project, I am open to your ideas. I am currently writing a module around the question of how different hormones or growth factors that appear to use the same signal transduction pathway (the MAP kinase pathway) result in different cellular outcomes. The goal is to have a quantitative module (computer based) to test different hypotheses of how this occurs and how small changes will affect the ability of a cell to respond appropriately.

The main tools we use in the lab include fluorescence and uv/vis spectrotroscopy to study a variety of samples. We also assay for lipid content, measure total protein, sometimes run protein gels, isolate biological membranes using differential centrifugation and use the new microtiter plate reader for enzyme assays.

I welcome students who are interested in exploring one of these or a related idea via independent study or research or a summer research experience.