Part:BBa_K5398020

This part encodes the TRn4-mfp5 fusion protein, which combines the adhesive properties of mfp5 with the special function of TRn4.The TRn4-mfp5 fusion protein combines two proteins: mfp5 from Mytilus foot proteins and TRn4 from squid ring teeth proteins. Mfp5 is derived from Mytilus, known for their ability to adhere to different materials' surfaces. This adhesion is primarily driven by the tyrosine residues in mfp5, which, upon oxidation by tyrosinase, are converted into dopamine. Dopamine forms π-π stacking interactions and hydrogen bonds with various substrates, including metal, glass, and polymer surfaces. This ability allows mfp5 to provide the bioadhesive strength that is crucial for surface attachment in various environments. TRn4 consists of a four-time repeated sequence derived from squid ring teeth proteins. The structural strength of squid ring teeth is attributed to the formation of β-sheets, which allow hydrogen bonding between protein strands. In TRn4, this repetitive sequence enables robust structural integrity, as the β-sheets can bond with other β-sheet structures.The fusion of mfp5 and TRn4 creates a unique protein that leverages the adhesive capabilities of mfp5 and the function of TRn4. When exposed to tyrosinase, the mfp5 portion generates dopamine, allowing the fusion protein to adhere to various materials through strong molecular interactions. The β-sheets in TRn4 allow hydrogen bonding between TRn4 and other repeated squid ring teeth protein. This fusion protein has the potential for applications in surface coatings, and bio-inspired materials that require both strong adhesion and mechanical stability. The combination of mfp5’s versatile binding properties and TRn4’s structural offers an innovative solution for challenges in areas such as marine technology, biomedical adhesives, and sustainable material development.

To validate the functionality of the fusion protein, we designed bacteria expressing TRn4-mfp5.We constructed the pET-SUMO vector, after culturing at 37°C for 4 hours, extracted the proteins for SDS-PAGE and Coomassie Brilliant Blue staining analysis.

We purified SUMO-Mfp6 using a HiTrap Ni-NTA column. The purified protein was verified by SDS-PAGE and was found to be present mostly in the 300 mM imidazole elution fraction.

https://static.igem.wiki/teams/5398/trn4-mfp5/1.webp Protein purification experiment (different imidazole concentrations). Lane 1: Protein - Binding buffer. Lane 2: 20 mM imidazole elution. Lane 3: 50 mM imidazole elution. Lane 4: 150 mM imidazole elution. Lane 5: 300 mM imidazole elution. Lane 6: 500 mM imidazole elution. Lane 7: Supernatant. Lane 8: Impurities.