Team:Sorbonne U Paris/Proof Of Concept

IGEM

Let's set the context…

The main proof we had to provide is that the undecapeptide has the same radioprotective effect as the decapeptide mentioned in our main source article, as our transformed cells will express the undecapeptide. The only difference between those two is the presence of the amino acid methionine at the beginning of the sequence.

Did we succeed?

To achieve that evidence, we tested the two peptides in both in vitro and in vivo assays. Unfortunately, our results weren’t conclusives. We did not have time to test the antioxidant capacity of both peptides in vivo with FDA, as we lost a lot of time working with Evans blue. In vitro, we did not succeed in characterizing the activity in LDH in the presence of the MDP or MUP complexe (manganese - peptide - pyrophosphate), as the enzymatic activity wasn’t repeatable between experiments.

Conclusion & what could be improved !

Furthermore In “MDP: A Deinococcus radiodurans Mn2+-Decapeptide Complex Protects Mice from Ionizing Radiation”, the article that we relied on to design our project, researchers tried several peptides sequences, that were less successful but still had a protective effect. With that in mind, we believe that the peptide potentializes the effect of Mn2+, so we strongly feel that the addition of only one Methionine to the sequence won’t change this effect much.

Despite the inconclusive results we remain convinced that the design of the experiments was relevant; a better preparation of the reagents and the use of a machine allowing us to carry out our experiments in one day would have made it possible to prove the effectiveness or ineffectiveness of the undecapeptide.