Part:BBa_K5302033

OmpA-VEGFR1D2-l2masking#18

This work is derived from pBBR-OmpA-VEGFR1D2 and pUC19-VEGFR-masking#18, and it has undergone codon optimization. This composite part combines OmpA(21.4kda) and VEGFR1D2(approximately 12kda), and it adds a fragment as a mask. We succeeded in transferring this plasmid into Escherichia coli Nissle 1917 and let it express VEGFR1D2. The plasmid uses lac promotor and has kanamycin resistence.

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This part is a peptidic mimics of VEGF α1 helix, it is derived from VEGF-B L1 and forms a helix structure. It exhibits high affinity for VEGFR-like receptors, with an IC50 value of 10 μM, allowing it to effectively compete with VEGF for binding to VEGFR. Consequently, this peptide has been utilized as a masking agent. Upon administration into the human body, it preemptively binds to VEGFR, preventing VEGF from engaging with the receptor. Given that matrix metalloproteinases (MMPs) are present at high concentrations in the tumor microenvironment (TME), they can degrade this VEGFR-masking peptide (designated as #29). This degradation allows VEGF to subsequently bind to the VEGFR-like receptors, triggering their activation. Therefore, this peptide functions as a biological switch, becoming active when exposed to the TME upon the entry of engineered chimeric nanoparticles (Escherichia coli Nissle 1917).

Figure 1. IC50 determination of peptides (4, 6, 14, 15, 16, 18, and 19). All peptides were prepared at concentration of 200 μM and then diluted successively by a factor 2 to 3.125 μM. The percentage of btVEGF-A165 displaced at each concentration of peptides was determined. The curves and IC50 values of each peptide were finally obtained in GraphPad Prism. Each peptide was tested in triplicate in two independent experiments

Figure 2. Structure of VEGFR1D2 and mask when they bind with each other

Figure 3. Structure of VEGFR-mask-#18

Sequence and Features

Assembly Compatibility:

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