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Team:INSA-Lyon/Project/Modeling/Previsions
From 2010.igem.org
Previsions
We are realizing this modelling to predict how many proteins of interest can be add on each granule. This protein will be associated with the phasins, by a fusion construction.
Estimation of the number of proteins present on the surface of granules.
Thomas Bäckström, Jane A Brockelbank and Bernd HA Rehm, (New Zealand), had published some interesting data about phasins and granules.(“Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting: functional display of the mouse interleukin-2 and myelin oligodendrocyte glycoprotein”).
In their experiments , they manage to extract 3g of proteins from a liquid culture containing 1011 granules by liter. It corresponds to 0,03 ng of protein in each granule.
1011 granules ↔ 3 g of proteins
1 granule∶3.10-11 g of proteins.
The phasins are the most numerous proteins of the granules. We can make the hypothesis that these 3g of proteins correspond to 3g of phasins. The average molecular weight of the phasins is about 70 kDa. We can now estimate the quantity of proteins in mole.
Average weight of phasin∶70 kDa.
70 000 g ↔ 1 mole of protein.
3.10-11 g ↔ 4,29.10-16 mole
Now, we can calculate the number of phasins present in each granule, using the Avogadro constant.
Na=6,022.1023 entities / mol
Nprotein=Na×4,29.10-16=258 343 800 proteins.
It seems that each granule presents about 2,6 108 proteins on its surface, corresponding to 330 proteins by nm².
