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Team:Dundee/Project/PP1Capacities
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<p>We considered the volumes of the bacteria and PP1 and used a cube approximation that took into account volume which was wasted, in packing, by the spherical shape of the protein. For this model we assumed there were no other surface proteins and protein production was not limited by any factors.<br><br> | <p>We considered the volumes of the bacteria and PP1 and used a cube approximation that took into account volume which was wasted, in packing, by the spherical shape of the protein. For this model we assumed there were no other surface proteins and protein production was not limited by any factors.<br><br> | ||
| - | Calculations show the maximum number of PP1 which can fit on the surface of B.subtilis is between 60 000 -70 000. From the average we can calculate that the number of bacterial mops required to clean a toxic level of microcystin in a litre of water is 1.40 x 10<sup>10</ | + | Calculations show the maximum number of PP1 which can fit on the surface of B.subtilis is between 60 000 -70 000. From the average we can calculate that the number of bacterial mops required to clean a toxic level of microcystin in a litre of water is 1.40 x 10<sup>10</sup>.<br><br> |
In <i>E. coli</i>, PP1 which would bind microcystin is free-flowing in the periplasm. The volume of the periplasm is much greater than the surface of <i>B. subtilis</i>. Therefore <i>E. coli</i> has the capacitive potential to be a more efficient mop. The maximum number of PP1 which can be packed into the periplasm is between 150 000 -200 000. Consequently, less bacterial mops are required to clean the same level of microcystin: 0.52 x 10<sup>10</sup>.<br><br> | In <i>E. coli</i>, PP1 which would bind microcystin is free-flowing in the periplasm. The volume of the periplasm is much greater than the surface of <i>B. subtilis</i>. Therefore <i>E. coli</i> has the capacitive potential to be a more efficient mop. The maximum number of PP1 which can be packed into the periplasm is between 150 000 -200 000. Consequently, less bacterial mops are required to clean the same level of microcystin: 0.52 x 10<sup>10</sup>.<br><br> | ||
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Revision as of 10:10, 2 October 2013
PP1 Capacities
Introduction
Microcystin’s toxic action lies in its ability to bind to the human Protein Phosphatase 1 (PP1). Microcystin covalently binds to PP1 in a one-to-one manner. Therefore higher binding potentials are achieved through having larger amounts of PP1 in the bacterial chassis E. coli and B. subtils.
The two options explored for our mop bacteria were to export PP1 to the periplasm of E. coli and onto the membrane surface of B. subtilis. We investigate the PP1 capacity of both chassis options using geometrical packing. This then allows us to determine which chassis has a higher microcystin binding potential.
Theory
We considered the volumes of the bacteria and PP1 and used a cube approximation that took into account volume which was wasted, in packing, by the spherical shape of the protein. For this model we assumed there were no other surface proteins and protein production was not limited by any factors.
Calculations show the maximum number of PP1 which can fit on the surface of B.subtilis is between 60 000 -70 000. From the average we can calculate that the number of bacterial mops required to clean a toxic level of microcystin in a litre of water is 1.40 x 1010.
In E. coli, PP1 which would bind microcystin is free-flowing in the periplasm. The volume of the periplasm is much greater than the surface of B. subtilis. Therefore E. coli has the capacitive potential to be a more efficient mop. The maximum number of PP1 which can be packed into the periplasm is between 150 000 -200 000. Consequently, less bacterial mops are required to clean the same level of microcystin: 0.52 x 1010.
Results
E. coli can store a significantly larger amount of PP1 than B. subtilis. This is because the volume of the periplasm in E. coli is much greater than the available surface volume of B.subtilis.
The maximum number of PP1 which can fit onto the surface of B. subtilis is between 60,000 -70,000, whereas the maximum number of PP1 which can be packed into the periplasm of E. coli is between 150,000 -200,000.
Consequently the E. coli chassis has a greater PP1 capacity and higher microcystin binding potential. Therefore using E. coli requires fewer cells to mop up a fixed concentration of microcystin, making it a more efficient mop. .
As a result we focussed the wet team’s time and efforts more on developing the E. coli mop to form the prototype ToxiMop.
