AbstractOur group is broadly focused on understanding and controlling the intersection of biology and materials at the molecular level. This intersection is critical in many areas of biotechnology where proteins and enzymes are integrated into or in constant contact with materials, including biocatalysis, tissue engineering, drug delivery, biosensing, and therapeutic protein formulation. In line with this interest, we have developed a novel approach to elucidate the structure and transient behavior of protein molecules at the solution-solid interface based on dynamic single-molecule tracking. This approach, which is uniquely sensitive to structural and interfacial dynamics, includes the use of high-throughput tracking of protein molecules by means of internal reflection fluorescence (TIRF) microscopy in combination with intramolecular as well as intermolecular Forster resonance energy transfer (FRET). An important aspect of this approach is the use of bioothogonal labeling techniques to site-specifically introduce donor and acceptor fluorophores, which allow fluctuations in FRET efficiency to be correlated with changes in protein structure. Notably, in this approach, as many as 106 protein molecules are tracked as they adsorb, desorb, diffuse, and simultaneously undergo conformational changes and/or intermolecular associations, permitting the statistical identification of dynamic, spatial, and population heterogeneity. The subsequent correlation of these dynamic behaviors on a molecule-by-molecule basis via large-scale multi-variate analyses, moreover, provides new insights into the connection between interfacial dynamics and protein structure. This talk will specifically focus on the application of this approach to understand the connection between protein dynamics and conformation as well as function, and the implications of this understanding to control protein and cellular interactions with materials.
Bio SketchJoel Kaar is an Associate Professor in the Chemical and Biological Engineering Department at the University of Colorado Boulder and currently serves as an Associate Chair in the department. Prior to joining he faculty at CU in 2010, he received his BS and PhD under Professor Alan Russell in chemical engineering from the University of Pittsburgh. Additionally, he was a postdoctoral associate at the Medical Research Council Centre for Protein Engineering in Cambridge, England, in Professor Sir Alan Fersht’s group. He has held an MRC Career Development Fellowship (2008-2010) and received the US Army Young Investigator (2012), NSF CAREER (2015), CU Department of Chemical & Biological Engineering Outstanding Junior Faculty (2016), and CU Provost’s Faculty Achievement(2016) awards.