AbstractOur ever-increasing understanding of how proteins fold has allowed the design of completely new peptides and proteins from first principles. So-called de novo protein design opens opportunities for the generation of novel biomaterials with easily tuneable properties. For instance, there are now several examples of de novo designed self-assembling peptide systems that form hydrogels for in vitro cell culture and tissue engineering. However, owing to the relative infancy of these systems, they have not been as well explored as similar scaffolds derived from natural sources or synthetic polymers. Studies often do not exploit the biggest asset of such designed systems – an ability to tune scaffold properties through a fundamental understanding of its makeup.
This thesis presents work to tune the chemical and physical properties of one such self-assembling peptide hydrogel; hydrogelating self-assembling fibres (hSAFs). This scaffold consists of two de novo designed α-helical peptides that form a heterodimeric coiled coil and subsequently fibrous structures. I demonstrate that this scaffold can support the growth of primary neurons and that, by modifying the sequence of the underlying peptides, I can generate scaffolds with varying viscoelastic properties. In addition, I show that both peptides and proteins can be incorporated into the scaffold, in a spatially controllable manner. Primary neuronal responses to these scaffolds are assessed to demonstrate the applicability of hSAFs as a modular and tuneable scaffold for neurons.
Another area in which de novo protein design might be utilised is the construction of novel biosensors. Recently, the Woolfson group demonstrated the differential binding of lipophillic small molecules to de novo designed α-helical peptide assemblies with solvent accessible pores. Here, I use an array of these peptides to differentiate between different fatty acids.
These studies go some way to realising the potential of protein design to deliver novel biomaterials with real-world applications.
|Date of Award||24 Mar 2020|
|Supervisor||Dek N Woolfson (Supervisor) & Jeremy M Henley (Supervisor)|