We are exploring the specific rules and general paradigms that govern protein self-assembly. In particular we are concentrating on how proteins un-fold, and self-assemble into fibrillar structures, and subsequently into an array of higher ordered supramolecular structures on the micro, meso and macroscopic length-scales. We are mapping out the phase behaviour of such systems to understand the influence of concentration, pH, ionic strength, temperature and presence of the denaturing agents such as sodium dodecyl sulfate (SDS). This has particular relevance for biopharmaceutical applications and we are also using the knowledge to design novel biomaterials for therapeutic and tissue engineering applications.
The organisation and dynamics of such systems at the air-water interface are also of interest.
From Fibres to Networks Using Self-Assembling Peptides.
Molecular self-assembly is a powerful tool for the preparation of materials with a wide variety of properties. This is illustrated by the abundance of self-assembled proteins and polysaccharides encountered in nature. In particular peptide materials are attracting increasing attention as small peptides are easy to design and synthesise with defined structure and function that self-assemble into 3D structures that are able to support the growth of a wide of variety of cell types. However their effective design and application is currently limited as the fundamental link between building block structure, mesoscopic structure, material properties and cell response has yet to be elucidated.
Our group is working towards addressing this by focussing on a number of key-issues to enable understanding and control of peptide self-assembly. Consequently we will be able to direct the morphology (e.g.: fiber size, porosity, roughness) and mechanical properties (e.g.: modulus, viscosity) of our materials and tailor them to specific application needs. In particular we are elucidating the molecular drivers for peptide self-assembly across the length scales by synthesising octa peptides with different amino acid sequences to systematically examine the effect of hydrophobicity, charge distribution and amino acid size/type. We are also fully characterising the structure and properties of the functional self-assembled networks and exploring their potential for therapeutic and clinical application.
We are interested in understanding and manipulating molecular behaviour at the air-liquid and liquid-liquid interfaces. One avenue we are exploring focuses’ on the ability of surfactants and polymers to promote, or inhibit, crystallization of small molecules. For example we are using surfactant and hydroxyl based polymers to promote ice crystallisation at the oil-water and air-water interfaces which has implications for the ice-cream industry. This work will be extended to investigate the effect of antifreeze proteins on ice crystal morphology