Investigating expression conditions used to synthesize recombinant proteins

• Akshay Patel, Biomedical Engineering, University of Delaware

• Kristi Kiick, Biomedical Engineering, University of Delaware

Elastin-like polypeptides (ELPs) are engineered peptides that mimic the function of elastin. ELPs have desirable mechanical properties such as elasticity and recoil, which, in combination with coiled-coiled peptides can be used to create thermoresponsive material through recombinant synthesis. As ELPs are strongly responsive to pH and temperature, they are highly tunable. The biocompatibility of ELPs makes these materials a promising candidate for many biomedical applications, including drug delivery carriers. Using recombinant synthesis, our goal was to produce these peptides with sufficient levels of both yield and purity. The expression of these proteins was done through the use of E. Coli bacteria and purified using denaturing conditions. We modified conditions and maximized the yield and purity. Characterization of the peptides was done using SDS-PAGE and mass spectrum, which analyzed the molecular weight in order to identify any impurities and determine overall purity of the product. Among the sequences of ELP that we tested, we observed that the 4h expression time yielded the highest purity and was the most optimal, resulting in a two-fold increase in yield compared to the 18h and 36h expressions.