ReviewCite this article: Kurylowicz M, Paulin H, Mogyoros J, Giuliani M, Dutcher JR. 2014 The effect of nanoscale surface curvature on the oligomerization of surface-bound proteins. J. R. Soc. The influence of surface topography on protein conformation and association is used routinely in biological cells to orchestrate and coordinate biomolecular events. In the laboratory, controlling the surface curvature at the nanoscale offers new possibilities for manipulating protein-protein interactions and protein function at surfaces. We have studied the effect of surface curvature on the association of two proteins, a-lactalbumin (a-LA) and b-lactoglobulin (b-LG), which perform their function at the oil-water interface in milk emulsions. To control the surface curvature at the nanoscale, we have used a combination of polystyrene (PS) nanoparticles (NPs) and ultrathin PS films to fabricate chemically pure, hydrophobic surfaces that are highly curved and are stable in aqueous buffer. We have used single-molecule force spectroscopy to measure the contour lengths L c for a-LA and b-LG adsorbed on highly curved PS surfaces (NP diameters of 27 and 50 nm, capped with a 10 nm thick PS film), and we have compared these values in situ with those measured for the same proteins adsorbed onto flat PS surfaces in the same samples. The L c distributions for b-LG adsorbed onto a flat PS surface contain monomer and dimer peaks at 60 and 120 nm, respectively, while a-LA contains a large monomer peak near 50 nm and a dimer peak at 100 nm, with a tail extending out to 200 nm, corresponding to higher order oligomers, e.g. trimers and tetramers. When b-LG or a-LA is adsorbed onto the most highly curved surfaces, both monomer peaks are shifted to much smaller values of L c . Furthermore, for b-LG, the dimer peak is strongly suppressed on the highly curved surface, whereas for a-LA the trimer and tetramer tail is suppressed with no significant change in the dimer peak. For both proteins, the number of higher order oligomers is significantly reduced as the curvature of the underlying surface is increased. These results suggest that the surface curvature provides a new method of manipulating protein-protein interactions and controlling the association of adsorbed proteins, with applications to the development of novel biosensors.

Secondary school curricula in Canada for subjects like science, technology, engineering, and math (STEM) often focus on surface-level learning. While frequently believed to be a precursor for later complex and in-depth studies, such approaches to teaching and learning fail to adequately prepare students for life outside of the classroom, including for future studies in their field of choice. In response to demands for STEM programming that inspires critical thought over rote standardizable knowledge, in 2016, Discovery was created. An interdisciplinary program operated out of the University of Toronto’s Faculty of Applied Science and Engineering, Discovery symbolizes a participatory partnership between the University of Toronto and local secondary schools to support inquiry-based learning for entire classrooms of high school students on a longitudinal basis. Discovery Instructors—consisting of multilevel post-secondary students—work alongside secondary school educators to devise problem-based projects that address key Ontario curriculum targets. Over the course of a semester, high school students are guided by university Instructors to engage in collaborative projects in biology, chemistry, and physics to expand their learning portfolios beyond the confines of a traditional classroom. However, while Discovery seeks to diversify learning for all involved, educator development for Discovery Instructors has remained largely implicit. In this study, we will introduce a teaching development course into Discovery’s Instructor preparation. Within a blended online learning environment across seven weekly modules, Instructor assessment will consist directly of discussion boards containing content- and reflection-based prompts using holistic rubrics and indirectly via mentored students’ performance. A pilot program is currently underway with a sample of enrolled Instructors with data to be collected as the program progresses.