Abstract: The ability to control the self-assembly of biological molecules to form defined or functional structures with a high degree of predictability is a central aim for soft matter science and synthetic biology. While this is possible for a variety of colloidal materials, it has been more difficult to achieve for proteins. In large part, this is due to the complex chemical nature of the protein surface, which influences the assembly process. It is therefore important to understand this complexity to reveal the mechanisms underlying important processes such as protein crystallization, the pathogenesis of protein condensation diseases, the aggregation of proteins during industrial manufacture and the formation of protein based materials. Recent results probing the extent to which protein surface anisotropic interactions influence protein self-assembly will be presented. Using phase diagrams for human gamma D-crystallin (a protein found in the human eye lens), both mutagenesis and chemical modification of the protein surface are used to demonstrate the impact of altering the protein surface chemistry. We will demonstrate the even small change to the protein surface can dramatically alter its phase behavior. Finally, I’ll show an example of how knowledge of protein phase diagrams can help in the rational design of advanced protein based materials.