Team:INSA-Lyon/Project/Stage2/Strategy
From 2010.igem.org
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<h2> Strategy</h2> | <h2> Strategy</h2> | ||
- | <br/> | + | <br/><br> |
- | <br | + | |
- | <h3>Storage | + | <h3><font color="purple">Storage lipid</font></h3><br><br> |
- | |||
<p> | <p> | ||
- | + | Many lipids are nowadays well-known to be very useful for health as DHA and EPA. | |
- | Granules are inclusion bodies of PHB and then a storage lipids drop. <br | + | Granules are inclusion bodies of PHB and then a storage lipids drop.<br><br></p> |
- | < | + | <p> |
+ | We wanted to test the hypothesis: if there are overproduced lipids inside the bacteria, they would be stored inside the PHB granules.It is less demanding for the bacteria, from an energetic point of view, to store it inside the PHB granules than to create another specific inclusion body. <br/><br/></p> | ||
- | < | + | <p>B-carotene (red-orange) and lycopene(red) are carotenoids pigments which are made of 40 carbons with isoprene units. Then we can observe the position of those proteins into the bacteria, thanks to the pigment coloration. Moreover, those parts are already ligated as composite parts in the registry under the control of the pBad/araC promoter which is induced by arabinose <a href="http://partsregistry.org/Part:BBa_I0500"><anne1><u>(I0500)</u></anne1></a>. |
- | <a href="http://partsregistry.org/Part:BBa_I0500"><anne1 | + | We use the plasmids <a href="http://partsregistry.org/Part:BBa_K274220">BBa_K274220</a> and <a href= "http://partsregistry.org/Part:BBa_K274120">BBa_K274120</a>. <br/><br/></p> |
- | We use the plasmids <a href="http://partsregistry.org/Part:BBa_K274220">BBa_K274220</a> and <a href= "http://partsregistry.org/Part:BBa_K274120">BBa_K274120</a>. <br/><br/> | + | |
- | < | + | <p> |
- | The first are long carbon | + | Beta-carotenes and lycopenes are molecules chemically really different from the PHB. |
+ | The first are long carbon chains with isoprene units (polyisoprenes) whereas PHB are polyesters.<br><br><br> | ||
</p> | </p> | ||
<div style="text-align: center;"> | <div style="text-align: center;"> | ||
- | <img | + | <img src="http://lh4.ggpht.com/_Uc3bmii-yi0/TMgoVVQGVlI/AAAAAAAAAmg/An6eptPxIqs/strategyStage2Molecules.PNG" titre="Molecules" alt="Molecules"/> |
- | + | <br><br><br><br> | |
- | + | ||
- | < | + | |
- | < | + | |
</div> | </div> | ||
<p> | <p> | ||
- | The properties that their structure confers to the molecule could explain that carotenoids cannot enter into the granules, but if our hypothesis is borne out, we have good hope that smaller carbon chains as DHA and EPA would be stored into the granules as well.<br/><br/> | + | The properties that their structure confers to the molecule could explain that carotenoids cannot enter into the granules, but if our hypothesis is borne out, we have good hope that smaller carbon chains as DHA and EPA would be stored into the granules as well.<br/><br/></p> |
- | In order to realize this experiment, we co-transformed our <a href="https://2010.igem.org/wiki/index.php?title=Team:INSA-Lyon/Project/Stage1/Strategy | + | <p> |
+ | In order to realize this experiment, we co-transformed our <a href="https://2010.igem.org/wiki/index.php?title=Team:INSA-Lyon/Project/Stage1/Strategy">pILI1 plasmid</a> producing PHB granules, and simultaneously a carotenoid plasmid. | ||
</p><br> | </p><br> | ||
+ | |||
<br/> | <br/> | ||
- | < | + | <h3><font color="purple">Purification of protein</font></h3><br><br> |
- | < | + | |
- | + | ||
- | < | + | |
- | <br | + | |
- | |||
- | < | + | <p> |
- | Based on Banki 2005 we designed a self cleavable fusion protein that we aim to insert in the | + | We wanted to use the PHA granules as a mean of purification for molecules produced in E.coli. |
+ | Based on Banki 2005 we designed a self cleavable fusion protein that we aim to insert in the granules membrane. | ||
To achieve our goal, we used the protein phasin which is present constitutively in the original bacterial operon. The publication emphasized that the addition of a second phasin increase the rate of purification. | To achieve our goal, we used the protein phasin which is present constitutively in the original bacterial operon. The publication emphasized that the addition of a second phasin increase the rate of purification. | ||
As lipid bodies, the granules can be extracted from the bacteria quite easily with the phasins attached on it. | As lipid bodies, the granules can be extracted from the bacteria quite easily with the phasins attached on it. | ||
Then to recuperate the molecule we want to purify, we added behind the phasins a self cleavable protein which breaks under pH 6. | Then to recuperate the molecule we want to purify, we added behind the phasins a self cleavable protein which breaks under pH 6. | ||
- | <br/><br/> | + | <br/><br/></p> |
- | + | ||
- | <br/><br/> | + | <p> |
- | We sent this sequence to Mr gene. Unfortunately because of the repetition of the phasin sequence, Mr gene could not | + | To design the part, we chose to use the sequence of phasin already designed by the team of Utah state in 2009 (<a href="http://partsregistry.org/Part:BBa_K208001">Part:BBa_K208001</a>). And we found the sequence of the self cleaving protein delta.I-CM mini intein from mycobacterium tuberculosis described in the publication in a patent. There was no restriction site forbidden by iGEM on the sequence so we used it directly. We linked those sequences using the same intersequences as in the article. At the ends of the whole sequence, we added the fusion standard biobrick sequence. |
- | So we | + | |
+ | <br/><br/></p> | ||
+ | |||
+ | <p> | ||
+ | We sent this sequence to Mr gene. Unfortunately because of the repetition of the phasin sequence, Mr gene could not synthesize the right sequence. | ||
+ | So we had to redesign our sequence in two parts: one phasin and one phasin+ intein. | ||
Each part have fusion biobrick standart. | Each part have fusion biobrick standart. | ||
<br /><br /> | <br /><br /> |
Latest revision as of 00:28, 28 October 2010
Strategy
Storage lipid
Many lipids are nowadays well-known to be very useful for health as DHA and EPA.
Granules are inclusion bodies of PHB and then a storage lipids drop.
We wanted to test the hypothesis: if there are overproduced lipids inside the bacteria, they would be stored inside the PHB granules.It is less demanding for the bacteria, from an energetic point of view, to store it inside the PHB granules than to create another specific inclusion body.
B-carotene (red-orange) and lycopene(red) are carotenoids pigments which are made of 40 carbons with isoprene units. Then we can observe the position of those proteins into the bacteria, thanks to the pigment coloration. Moreover, those parts are already ligated as composite parts in the registry under the control of the pBad/araC promoter which is induced by arabinose
Beta-carotenes and lycopenes are molecules chemically really different from the PHB.
The first are long carbon chains with isoprene units (polyisoprenes) whereas PHB are polyesters.
The properties that their structure confers to the molecule could explain that carotenoids cannot enter into the granules, but if our hypothesis is borne out, we have good hope that smaller carbon chains as DHA and EPA would be stored into the granules as well.
In order to realize this experiment, we co-transformed our pILI1 plasmid producing PHB granules, and simultaneously a carotenoid plasmid.
Purification of protein
We wanted to use the PHA granules as a mean of purification for molecules produced in E.coli.
Based on Banki 2005 we designed a self cleavable fusion protein that we aim to insert in the granules membrane.
To achieve our goal, we used the protein phasin which is present constitutively in the original bacterial operon. The publication emphasized that the addition of a second phasin increase the rate of purification.
As lipid bodies, the granules can be extracted from the bacteria quite easily with the phasins attached on it.
Then to recuperate the molecule we want to purify, we added behind the phasins a self cleavable protein which breaks under pH 6.
To design the part, we chose to use the sequence of phasin already designed by the team of Utah state in 2009 (Part:BBa_K208001). And we found the sequence of the self cleaving protein delta.I-CM mini intein from mycobacterium tuberculosis described in the publication in a patent. There was no restriction site forbidden by iGEM on the sequence so we used it directly. We linked those sequences using the same intersequences as in the article. At the ends of the whole sequence, we added the fusion standard biobrick sequence.
We sent this sequence to Mr gene. Unfortunately because of the repetition of the phasin sequence, Mr gene could not synthesize the right sequence.
So we had to redesign our sequence in two parts: one phasin and one phasin+ intein.
Each part have fusion biobrick standart.