Revision as of 14:13, 20 September 2015

Pcons+B0034+Lpp-OmpA-N+scFv(Anti-VEGF)

Introduction:

Fig.1 Pcons+B0034+Lpp-OmpA-N+scFv(Anti-VEGF)

By ligating the constitutive promoter (BBa_J23101), strong ribosome binding site (BBa_B0034) and Lpp-OmpA-scFv, we were able to display scFv(Bevacizumab) outside the E.coli cell membrane.

This year we want to provide a customized platform. We provide two libraries of Pcon+RBS+OmpA-scFv and Pcons+RBS+Fluorescence+Ter into E. coli. Therefore, our customers can choose any scfv and any fluorescence protein. Our team will then co-transform the two plasmids, which helps us tailor our product to the wishes of our customers.

Experiment

1.Cloning

Fig.3The PCR result of the Pcons+B0034+Lpp-OmpA-N+scFv. The DNA sequence length is around 1100~1300 bp, so the PCR products should appear at 1300~1500 bp.

After assemble the DNA sequences from the basic parts, we recombined each Pcons+RBS+Lpp-OmpA-N+scFv gene to PSB1C3 backbones and conducted a PCR experiment to check the size of each of the parts. The DNA sequence length of these parts is around 1100~1300 bp. In this PCR experiment, the scFv products size should be near at 1300~1500 bp. The Fig. 3 showed the correct size of the scFv, and proved that we successful ligated the scFv sequence onto an ideal backbone.

Fig.4Pcons+B0034+Lpp-OmpA-N+scFv(Anti-VEGF)

After cloning the part of anti-VEGF, we were able to co-transform anti-VEGF with different fluorescence protein into our E. coli.
The next step was to prove that our co-transformed product have successfully displayed scFv of anti-VEGF and expressed fluorescence protein.
To prove this, we conducted the cell staining experiment by using the co-transformed E. coli to detect VEGF in the cancer cell line.

Negative control:
There are green fluorescent anti-VEGF E. coli stick on the cell’s surfaces as the anti-VEGF probes on E. colis successfully detect and bind with VEGF.

Fig.9 As results,there is no green fluorescent E. coli stick on the cell’s surface as there is no specific scFv displayed around the E.coli.

Fig.11 There are green fluorescent anti-VEGF E. coli stick on the cell’s surfaces as the anti-VEGF probes on E. coli successfully detect and bind with VEGF.

Modeling

In the modeling part, we discover optimum protein production time by using the genetic algorithm in Matlab.
We want to characterize the actual kinetics of this Hill-function based model that accurately reflects protein production time.
When we have the simulated protein production rate, the graph of protein production versus time can be drawn. Thus, we get the optimum protein production time Compared with the simulated protein production rate of time, our experiment data quite fit the simulation.

Fig.13 From this graph, the orange curve is the simulated protein expression. The blue curve is our experimental data. By comparing the orange curve and the blue curve, the blue curve quite fit the simulation. The orange curve reaches peak after growing about 13 hours. Thus, we can know that the E. Cotector can have maximum efficiency at this point.

Sequence and Features