Difference between revisions of "Part:BBa K5322032"

Revision as of 13:54, 1 October 2024

Lpp-OmpA-Programmed Cell Death 1 Ligand 1 Functional Domain [Mus musculus] Expression System

Usage and Biology

During the project, we considered that PD-L1 might be encapsulated by mussel foot protein (Mfp) during expression and release, potentially reducing therapeutic efficacy. To address this, we utilized the surface display system Lpp-OmpA(BBa_K5322035) to present our passenger protein PD-L1 on the outer membrane of E. coli. This would facilitate its binding with PD-1, enhancing effectiveness. Additionally, to demonstrate surface display, we inserted a flexible protein linker and a TEV protease recognition site(BBa_K5322036) between Lpp-OmpA and the PD-L1 functional domain. By incubating the cells with TEV protease, PD-L1 could be cleaved from OmpA. Detection of the PD-L1 functional domain in the supernatant would indirectly confirm the success of surface display. We designed the plasmid pET29a-J23119-Lpp-OmpA-GISS-TEVsite-PD-L1(Functional domain)-T7.

Figure 1-1 Plasmid pET29a-J23119-Lpp-OmpA-GISS-TEVsite-PD-L1(Functional domain)-T7

Construction of the plasmid

The target fragment was amplified by PCR, and the pET29a vector was amplified. The PCR product was subjected to gel electrophoresis (30 min, 120 V). After the product was purified, homologous recombination was performed and transformed into Escherichia coli DH5α. The plate was inverted and cultured at 37°C. After 16 hours, colony PCR was performed on a single colony. The results are shown in the figure.

Figure 2-1 Colony PCR

The colony PCR was successfully inoculated at 37°C, 220rpm, 12-16h, the plasmid was extracted and sent to the company for sequencing. The sequencing results are shown in the figure below.

Figure 2-2 Sequencing results

Protein characterization

Sequence and Features