| Summary: | Nanomaterials produced by molecular self-assembly has become one of the emerging technologies for the development of materials for the food, cosmetic and biotechnology industries. These materials exploit the unique properties of their molecular building blocks, which include natural molecules, such as peptides. Using the entire library of amino acids, consisting of 20 residues that are conserved across all life forms, a range of different materials can be created, such as hydrogels, emulsions, etc. However, such materials are normally found serendipitously or by complex molecular design and therefore the development of new systems has been challenging. In this thesis, a combination of computational and experimental techniques is used to predict, design, synthesize and apply a range of different tripeptides. Using design rules, a subset of tripeptides was chosen to examine their self-assembling ability. It was determined that peptides with cationic amino acids at the N-terminal position (KYF, KYW and KFF) promote the formation of nanofibers and hydrogelation whereas anionic amino acids form bilayer-like assemblies (DFF and FFD). Alteration of the peptides sequence disrupts the formation resulting in loss of ordered nanostructures. Exploiting this self-assembling process can result into different materials such as emulsions. Fibrous tripeptide assemblies have the ability to assemble at the water/oil interface stabilizing emulsions via interfacial nanofibrous networks, whereas anionic tripeptide assemblies form surfactant-like emulsifiers. These materials can be tuned to give different emulsion stabilities. The formation of tripeptides can be controlled using enzymatic methods where physiological conditions can be altered to selectively target different tripeptides. Conditions such as pH and temperature control peptide hydrolysis allowing for the retention of highly order peptide nanostructures. The promotion of highly order nanostructures is imperative and the presence of additive such as salts can influence the self-assembling structure formed. Different salts can interact with charged amino acids, which promote crosslinking between peptides creating new tripeptide nanomaterials.
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