An Undergraduate Biochemistry Lab Exploring Elastin-Like Polypeptide Behavior and Degradation: From Purification to Proteolysis

Abstract

The development of smart biomaterials that mimic the native extracellular matrix forms the basis for many innovations within the field of regenerative medicine. Elastin-like polypeptides (ELPs) are widely used in biomaterials due to their unique physicochemical properties. ELPs exhibit lower critical solution temperature behavior, meaning that, above their specific transition temperature, these polypeptides reversibly phase-separate and start to aggregate. Furthermore, their production via recombinant DNA techniques enables the incorporation of bioactive motifs such as enzyme-cleavable domains. Because of their attractive properties and broad applicability, the purification and characterization of ELPs are very relevant. Therefore, the goal of this laboratory experiment is to purify and characterize an ELP and to investigate its enzymatic degradation. Purification is done via inverse transition cycling, a technique that utilizes the thermoresponsive properties of ELPs. Students analyze the purity of the various fractions obtained during the purification process using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, they incubate the purified ELP with a protease and evaluate the success of the degradation. This practical provides students with both a theoretical background and practical experience in the fields of recombinant protein production and physical chemistry, which can be valuable for their future career paths in biochemistry, biomedical sciences, bioengineering, and biology.