(226a) (Invited Talk) Self-Assembled Protein Vesicles for Drug Delivery and Biocatalysis

Protein vesicles incorporating functional, globular proteins have potential in a number of bio-applications such as drug delivery, biocatalysis, and sensing. We have previously created protein vesicles from mCherry-zipper-ELP protein complexes where ELP is a thermo-responsive elastin-like polypeptide. As we aim to utilize these vesicles, additional knowledge is needed to replace mCherry with more useful functional proteins and provide stability. I will present the mapped vesicle phase space in terms of the surface charge and molecular weight of functional proteins capable of making protein vesicles. Protein surface charge was determined to have little effect on vesicle formation due to the relative high salt used to assemble vesicles. We implemented crosslinking strategies to stabilize vesicles at low or physiological salt concentrations following assembly to enable use in a range of environments. Molecular weight of the functional protein has a more significant effect than charge in the range studied (~20-80 kDa). Increasing the size of the functional protein headgroup decreases the size of the vesicles and increases their stability at lower molar ratios of functional protein to ELP. With this information, we have demonstrated assembly of biocatalytic vesicles with significant improvements in activity over soluble enzyme and produced vesicles for drug delivery capable of carrying and releasing therapeutic cargoes. The wide range of vesicle properties and functions exhibited in these examples, highlight the versatility of vesicles as functional protein materials.