Grant: Discovery Grants Program - Individual

My research focuses on the advancement of biophysical technology in the field of analytical ultracentrifugation (AUC) and related biophysical solution techniques. AUC is the method of choice for the characterization of colloidal materials. Advances in this field benefit basic research in biochemistry, physics, and material science, and provide improved characterization tools for industries like biopharma and synthetic polymer chemistry. For biopolymers and other nanomaterials, AUC offers the ability to study molecules and their assemblies under physiological conditions, where pH, ionic strength, reduction potential, temperature and other factors are easily modulated. As the new Canada 150 Research Chair for Biophysics, I have recently established the Canadian Center for Hydrodynamics, a premier laboratory equipped with three highly unique AUC instruments to accelerate biophysical research in Canada. This combination of tools is not available anywhere else, and leveraging the unique capabilities of these instruments, the goal of our proposed research is to advance previous efforts by developing new analysis protocols and software tools that will allow us to solve long-standing challenges in the following four fields: 1. Membrane proteins (MP). MPs are biologically important molecules, but notoriously difficult to study because of their poor solubility in aqueous solvents. We will embed MPs in well-defined nanodisks containing physiological phospholipids and characterize the complexes formed. Using differential labeling with fluorophores exhibiting unique extinction profiles we hope to clearly distinguish filled from empty nanodisks and embedded MPs, their oligomerization states, and their interactions with their targets, as well as misfolded and aggregated MPs. 2. Aggregating Systems (AS). ASs are challenging to study due to their excessive heterogeneity and lack of colloidal/chemical stability. We will focus on interactions of drug candidates with amyloid-ß to study their influence on disrupting or dissolving harmful amyloid oligomers or inhibit their formation. We will exploit the much enhanced scanning speed and multi-speed sedimentation of the new instruments to obtain detailed size and anisotropy distributions of highly heterogeneous aggregates. 3. Hetero Complexes (HC) with unique spectral properties. Broad-spectrum multi-wavelength detection will allow us to quantify stoichiometries, molar masses and binding strengths in the study of HCs. In collaboration with investigators at UL we will accelerate research in important biomedical and structural biology problems and develop novel tools for the study of HCs under physiological conditions. 4. Modeling of non-ideal transport. Analytes under high concentration conditions require modifications in the modeling and optimization codes in our UltraScan software. My team and I will develop finite volume solutions of the Lamm equation and create new optimization methods to cover such cases.