Grant: Discovery Grants Program - Individual

Fungi produce many proteins with unusual functions and biochemical properties. One such example are hydrophobins, which accumulate at hydrophilic-hydrophobic interfaces and reduce the surface tension of water so that fungi can breach the air-water interface and grow. Hydrophobins can also undergo structural rearrangement and self-assemble to form rodlets, which create an extremely durable and water repellent coating for fungal spores. Despite their potential to be used as biomaterials, a comprehensive, molecular-based understanding of how hydrophobins function is lacking. In particular, the mechanism by which hydrophobins self-assemble into rodlets is not clear. The overall goal of my research program is to gain a mechanistic understanding of hydrophobin assembly and to develop new applications for hydrophobins. Specifically, I aim to: 1. Identify sequences in hydrophobins that drive rodlet assembly and stability The solution structure of hydrophobins is known but it is unclear which regions of these proteins are needed for self-assembly. My research group will use site-directed mutagenesis and functional assays to determine which regions of hydrophobins are essential for their function. Finally, we will use nuclear magnetic resonance spectroscopy to characterize regions of hydrophobins that are most flexible and may be involved in the self-assembly process. These results will determine which regions of hydrophobins are required for self-assembly. 2. Determine the molecular structure of hydrophobin rodlets Using complementary techniques such as atomic force microscopy and solid-state nuclear magnetic resonance spectroscopy, the high-resolution structure of hydrophobin rodlets will be determined. This will allow us to determine why rodlets are so stable once assembled at a surface. 3. Engineer hydrophobins for applications involving surface functionalization As a proof-of-principle, my research group will investigate the ability of hydrophobins to enhance the activity of the plastic-degrading enzyme, PETase. PET (polyethylene terephthalate) is one of the most common plastics produced globally and much of it ends up in landfills or as garbage in the environment. Hydrophobins bind tightly to surfaces like plastic, and we will create a PETase-hydrophobin fusion protein that we anticipate will localize PETase to the plastic surface and enhance its plastic-degrading activity. This may provide a viable mechanism to degrade plastics that otherwise would not be recycled. This unique research program within Canada will provide insight into how hydrophobins can be used to create new biomaterials for applications like plastic degradation, which is of benefit to Canadians. Personnel in my group will develop skills in the fields of molecular biology, biophysics, protein engineering, and structural biology on a protein system that is directly applicable to the biotechnology industry.