Understanding the genetic fusion of thermoresponsive polypeptides mediating hierarchical nanostructure assembly of Coiled-Coil Bundlemers via molecular dynamic simulations*

The thermoresponsiveness and outstanding mechanical properties of elastin-like polypeptides (ELPs) and resilin-like polypeptides (RLPs) have been widely explored for producing nanoparticles, sensor platforms, and microstructured hydrogels. However, most of the previous studies focus on long polypeptide sequences with short ELP and RLP based sequences in stimuli-responsive materials having not been explored. In our studies, we applied molecular dynamics simulation with coarse-grained (CG) models to microscopically investigate the assembly pathways of newly designed RLP coiled-coil bundles conjugates and ELP coiled-coil bundles conjugates with different variations. Within the conjugates, the short protein sequences provided for thermoresponsiveness while the coiled coil 'bundlemer' components provide for a specific display of the thermoresponsive proteins. The thermoresponsive, noncovalent assembly into nanofibrillar assemblies of RLP coiled-coil bundles conjugates was successfully captured via CG model. For the ELP coiled-coil bundles conjugates, different hierarchical nanostructure assembly morphologies were observed such as nanodroplets or bilayer vesicles based on the design of the conjugates. Finally, a comparison between the simulation and experimental results revealed a high degree of agreement.