This is a developing aspect of the lab wherein purposefully engineered protein substrates are used for advanced clinical and general materials purposes. A thermostable protein nanoparticle (tES) was successfully engineered in August 2017 to aid in the expression and stabilization of recombinant proteins. tES provides steric accommodation and charge complementation to green fluorescent protein (GFPuv), horseradish peroxidase (HRPc), and Renilla luciferase (rLuc), improving yields of functional in vitro folding by approximately 100 fold. Encapsulated enzymes retain the ability to metabolize small molecule substrates, presumably via four 4.5 nm pores present in the tES shell. GFPuv exhibits no spectral shifts in fluorescence compared to a non-encapsulated control. Thermolabile proteins internalized by tES are resistant to thermal, organic, chaotropic, and proteolytic denaturation and can be released from the tES assembly with mild pH titration followed by proteolysis.