ABSTRACT We request funds to purchase an Optima Analytical Ultra Centrifuge (AUC) equipped with interference optics from Beckman Inc. AUC is a powerful, first principle, technique that provides in solution measurement of sample shape, size, and heterogeneity, in addition to measuring strengths of bio-molecular interactions. AUC enables the researcher to perform native-condition characterization of their protein of interest. The instrument will be housed in the Department of Biochemistry and Molecular Biology at the Saint Louis University School of Medicine. The instrument will support basic research of NIH-funded investigators at both the Medical School and in the College of Arts and Sciences. The AUC will also be pivotal in assessing sample homogeneity for structural analysis using cryo-electron microscopy. We describe projects from 4 major users with R01 NIH grants and 4 minor users that will benefit from the requested instrumentation. The user projects span a range of biomolecular interactions in DNA repair and recombination, blood clotting processes, protein aggregation in neurodegeneration, immunothrombosis, regulation of protein translation, laminopathies and ubiquitination processes. All these projects depend on biochemical analysis of the respective protein-protein and protein-substrate complexes and the AUC will be instrumental in establishing their oligomeric and biomolecular interaction properties. The new optima AUC will replace the existing older model ProteomeLab AUC which is now 15 years old and well past the serviceable age. The optima AUC is also redesigned to house the mechanical parts within the main chamber and possess much greater optical resolution and data capture properties. More importantly, the optima AUC is compatible with fluorescence detection capabilities that are currently under development. Training for the optima AUC will be primarily handled by members of the Antony research group who have more than a decade of experience using the instrumentation, sample preparation, and data analysis. Users (undergraduate & graduate students, postdoctoral fellows, and research associates) will be trained to independently use the AUC and instrument time will be determined using the existing scheduling system for departmental instrumentation. A local advisory committee will provide oversight of the AUC and its operations. The optima AUC will be an integral component of the biophysical instrumentation portfolio at Saint Louis University and will have a significant impact on the NIH-funded research.

PROJECT NARRATIVE Saint Louis University has a critical mass of NIH-funded investigators whose research has relied on an Analytical Ultracentrifuge for more than a decade. The new optima AUC will serve to replace this critical instrumentation and drive important biomedical research. The proposed users perform translational and basic research in cancer, neurodegeneration, cardiac and blood clotting processes, immunology, and many other areas.