Difference between revisions of "Part:BBa K5461000"

GST-csga-spytag
Description:
This part can be used to express Csga tagged with both a GST tag and SpyTag.

Csga has been shown to self-assemble into curli fibers and bind to cellulose, while SpyTag has been proven to tightly bind to SpyCatcher through an isopeptide bond. Thus, this construct can serve as a scaffold protein, acting as moduleII of our system. On one hand, it binds to cellulose, and on the other, it binds to SpyCatcher-tagged proteins. Therefore, using this part in conjunction with BBa_K5461000 enables the coupling of more functional proteins to cellulose, facilitating cellulose functionalization:

Results:
The biofilm protein Csga can be stained with Congo red, so we verified the expression of the Csga membrane protein using a Congo red agar plate assay. Following that, through liquid culture expression experiments, we successfully produced and collected filamentous precipitates:

After purification of Csga using a GST affinity chromatography column, the protein was further analyzed by Western blot. Protein samples were separated on a SDS-PAGE gel, transferred onto a PVDF membrane, and probed with an anti-GST antibody. The presence of Csga-GST was confirmed by the detection of the expected band size, indicating successful purification and expression

Next, we purified the colored protein using BBa_K5461001 as our proof-of-concept protein. After obtaining the purified protein, we validated the binding interactions between bacterial cellulose, the Curlis-SpyTag scaffold protein, and the SpyCatcher-POI. The results demonstrated that the scaffold protein system significantly enhances the binding efficiency between the target protein (POI) and cellulose.

Through this demonstration, we successfully validated the efficiency of the Curlis-Spy scaffold protein design and the plug-and-play nature of the system. In the future, we plan to provide more protein data.

Summary:
We have established a standard, offering a foundational and scalable platform that decouples protein functionality from its compatibility with cellulose. This allows future iGEM teams to focus on selecting proteins for cellulose modification without needing to worry about their binding capability to cellulose, providing a foundational framework for the development of functionalized cellulose.