Engineering principles of hydrophobin fusion proteins: Dissertation

The research presented in this thesis focuses on the design and use of hydrophobin fusion proteins for technological applications. Hydrophobins are small fungal proteins with interfacial function.This characteristic arises from a unique, bipolar structure. Hydrophobins also partition effectively in liquid two-phase systems. The aim of the work presented in this thesis was to connect the molecular function of the hydrophobin HFBI to other operational functionalities by methods of protein engineering.Proteins have become a central focus of reseach in the fields of biotechnology and material development. The vast interest is due to the inherently detailed structure of proteins, forming complex functionalities that build up to great application potential. Nature has created detailed and precise function to these molecules, which can be harnessed to build new materials. The art of protein engineering may be used to join and modify elements in new combinations.A central theme throughout this research was to evaluate aspects such as protein component stoichiometry, material geometry and charge effects, as well as holistic factors influencing application desing. Firstly, suitable model hydrophobin fusion proteins were designed and produced, and their functionality at liquid-liquid and solid-liquid interfaces was studied. In the following segment of this study, the functionality of the fusion proteins was assessed in model applicaions as a hybrid material with carbon nanoparticles. The results presented in this thesis demonstrate the design and use of protein functionalities for creation of biomolecular assemblies based on the self-assembly of hydrophobin HFBI. The solution equilibrium of class II hydrophobins plays a crucial role in the usability of its fusion derivatives, alongside with the mechanistic details of the interfacial assembly. The results were evaluated in the frame of the design process of hydrophobin fusion proteins. This process consists of an engineering step, a formulation step and a final application step. Thereby, this thesis highlights the importance of considering protein architecture and stoichiometry throughout the process.