Kenneth A. Christensen
Assistant Professor
Analytical Chemistry
Phone: (864) 656.0930
Office: 118 BRC
E-mail: kchris@clemson.edu
Research Interests | Publications | Current Sponsored Research
Dr. Christensen earned his B.S. degree in chemistry from Brigham Young University in 1992 and his Ph. D. in analytical chemistry from the University of Michigan in 1997. After graduation, he did postdoctoral work with Prof. Joel Swanson at the University of Michigan Medical School (Department of Microbiology & Immunology). In addition, he worked in Prof. John Collier's lab at Harvard Medical School (Department of Microbiology & Molecular Genetics) before joining the faculty at Clemson University.
Research Interests
Dr. Christensen’s lab works mainly in the dynamic and rapidly evolving field of bioanalytical chemistry. His lab develops methods and devices that apply optical spectroscopy, time-lapse microscopy, and modern analytical and biophysical techniques to questions in biochemistry, biophysics, cell- and microbiology. The lab focus is shared among three areas of active research
1) We are using novel capillary-channeled fibers and films as a flexible, low cost, and robust platform for a variety of bioanalytical measurements. These fibers and function as extremely simple microfluidic devices with outstanding fluid transport properties. A single fiber or film can be used as a disposable flow cytometer with similar throughput and sensitivity to a commercial instrument. We have constructed lateral flow assays with sensitivity enhanced 10x over standard assays and are currently developing a multiplexed assay for rapid analysis of gene expression from cell lysates, even from a single cell.
2) We are developing and using luminescent nanoparticles constructed from conjugated polymers, carbon, and silicon as extremely bright microscopy probes in cells, including a variety of ion-sensing nanoparticles for measurements of intracellular pH, Na+, K+, Ca2+, and Mg2+. These luminescent nanoparticles have enhanced properties that give them significant advantages over standard organic fluorophores, including low cytotoxicity, extremely high signal, and the ability to be trafficked to defined locations inside the cell.
3) We are developing and piloting novel fluorescence resonance energy transfer (FRET) based high throughput screening assays, aimed at identifying molecules that block protein-protein interactions with anthrax toxin receptors. Small molecules, peptides, and aptamers identified in these screens can identify antidotes for anthrax intoxication. In addition, since the anthrax receptors are involved in new blood vessel growth (angiogenesis), molecules identified by the screens will provide lead compounds for therapeutics for cancer and other diseases caused by aberrant angiogenesis
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Publications
Wu, C., Bull, B., Christensen, K. and McNeill, J., “Ratiometric Single-Nanoparticle Oxygen Sensors for Biological Imaging”, Angewandte Chemie International Edition, 48, 2741-2745 (2009)
Wu, C., Bull B., Szymanski, C., Christensen, K., and McNeill, J., “Multicolor Conjugated Polymer Dots for Biological Fluorescence Imaging”, ACS Nano, 2, 2415–2423 (2008)
Rogers, M.S., Christensen, K.A., Wigelsworth, D.J., Collier, R.J., and D’Amato, R.J., “Mutant Anthrax Toxin B-moiety (Protective Antigen) Inhibits Angiogenesis and Tumor Growth”, Cancer Research, 67, 9980-9985 (2007)
Evanoff, D.D. Jr., Heckel, J., Caldwell, T.P., Christensen, K.A., and Chumanov, G., “Monitoring DPA Release from a Single Germinating Bacillus subtilis Endospore via Surface-Enhanced Raman Scattering Microscopy”, Journal of the American Chemical Society, 128, 12618-12619 (2006)
Daniels, J.K., Caldwell, T.P., Christensen, K.A., and Chumanov, G., “Monitoring the Kinetics of Bacillus subtilis Endospore Germination via Surface-Enhanced Raman Scattering Spectroscopy”, Analytical Chemistry, 78, 1724-1729 (2006)
Shaughnessy, L.M., Hoppe, A.D., Christensen, K.A., and Swanson, J.A., “Membrane perforations inhibit lysosome fusion by altering pH and calcium in Listeria monocytogenes vacuoles”, Cellular Microbiology, 8, 781–792 (2006)
Christensen, K.A., Krantz, B.A., and Collier, R.J., “The assembly and disassembly kinetics of anthrax toxin complexes”, Biochemistry, 45, 2380-2386 (2006)
Qa’dan, M., Christensen, K.A., Zhang, L., Roberts, T.M., and Collier, R.J., “Membrane Insertion by Anthrax Protective Antigen in Cultured Cells”, Molecular and Cellular Biology, 25, 5492-5498 (2005)
Christensen, K.A.*, Krantz, B.A.*, and Collier, R.J., “Interaction of the 20 kDa and 63 kDa Fragments of Anthrax Protective Antigen: Kinetics and Thermodynamics”, Biochemistry, 44, 1047-1053 (2005)
Krantz, B.A., Trivedi, A.D., Cunningham, K., Christensen, K.A., and Collier, R.J., “Acid-induced Unfolding of the Amino-terminal Domains of the Lethal and Edema Factors of Anthrax Toxin”, Journal of Molecular Biology, 344, 739-756 (2004)
Pimental, R-A.L.*, Christensen, K.A.*, Krantz, B.A., Collier, R.J., “Anthrax toxin complexes: heptameric protective antigen can bind lethal factor and edema factor simultaneously”, Biochemical and Biophysical Research Communications, 322, 258–262 (2004)
Wigelsworth, D.J.*, Krantz, B.A.*, Christensen, K.A., Lacy, D.B., Juris, S.J., and Collier, R.J., “Binding Stoichiometry and Kinetics of the Interaction of a Human Anthrax Toxin Receptor, CMG2, with Protective Antigen”, Journal of Biological Chemistry, 279, 23349-23356 (2004)
“Polymer Dot Nanoparticles for Detection of Single Molecules in Live Cells”, National Institutes of Health-R01, 2007-2011
“Novel Angiogenesis Inhibitors Targeting the Anthrax Toxin Receptors”, National Institutes of Health-R01, 2008-2013
“Antiangiogenic Natural Products Targeting Anthrax Toxin Receptor 2”, Department of Defense—Breast Cancer Research Program Synergistic Idea Award Program, 2008-2010
EFRI-BSBA: Leipdoptera Proboscises as Prototypes of Multifunctional Fluidic Devices with Distributed Actuation and Sensing, National Science Foundation, 2009-2013
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