CAREER: Quantification of Prion Protein Sorption to Soil Components

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Pedersen 0547484 The main objectives of this NSF CAREER proposal are (1) to develop a highly sensitive, quantitative method for prion protein measurement, and (2) to quantitatively describe the association of prion proteins with surface-reactive soil minerals and to examine the factors influencing attachment to and detachment from these particles. Quantitative analytical methods for prion proteins are currently lacking. The PI therefore intends to exploit recent advances in proteomics to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for prion protein quantitation based on a signature peptide approach. The second objective will be addressed in a series of batch attachment and detachment experiments using the newly developed LC-MS/MS method for quantitation. The association of prion proteins to clay minerals and metal oxides will be examined as a function of pH to determine the influence of prion and mineral surface charge on attachment. Reversibility of prion protein attachment due to shifts in pH and the presence of surfactants and dissolved organic matter will be investigated in batch detachment experiments. The importance of electrostatic and hydrophobic interactions between prions and mineral surfaces will be explicitly examined. Experimental results will be interpreted within the framework of extended Derjaguin-Landau-Verwey-Overbeek theory. The PI will use atomic force microscopy to measure interaction forces between prion protein and a subset of mineral surfaces. From these experiments, the PI will derive sticking efficiencies to facilitate prediction of prion transport in porous media. Broader impacts: The LC-MS method is expected to have utility well beyond the environmental fate studies outlined in this proposal. The method has the potential to significantly impact medical and veterinary research and the diagnosis of transmissible spongiform encephalopathies. Improved understanding of prion attachment to soil components will naturally lead to the development of engineering applications based on our findings. The educational component of this career development plan focuses on integrating research and instruction and fostering increased interdisciplinarity in environmental engineering and science. The PI will develop a new graduate course on environmental colloid chemistry and a short course for practicing environmental professionals on the treatment and disposal of biological threat agents. Broader impacts will also be realized through enhanced K-12 education. The PI will extend an existing collaboration with a middle school science teacher to design, implement and evaluate an instructional unit on environmental engineering and science organized around inquiry- and discovery-based learning exercises. In addition to publishing research findings in leading journals, information about prions in the environment will be disseminated to a wider audience through a "display" in the UW Madison Virtual Museum of Minerals and Molecules. During the duration of the project, the PI will provide opportunities for undergraduate students to participate in research, with special consideration given to underrepresented minority applicants. The PI will leverage existing resources to reach his educational objectives such as UW NSF-funded Delta Program in Research, Teaching and Learning to provide opportunities for graduate students to develop skills in classroom teaching, preparation of instructional materials, informal education, teaching to diverse student audiences, teaching with technology and internships.