Leon: So I think this project can be broken down into multiple components listed below:
- Estrogen Detection
- We first need to design a mechanism for detecting environmental estrogens. Keep in mind that environmental estrogens are so dangerous to humans because they "trick" the body's natural estrogen receptors and thus cause the body to react as if there was an abnormally high levels of estrogen present in the body. Therefore, when designing these estrogen detecting devices, we should focus on how to recreate the actual estrogen receptors in the body so that not only will these artificial detectors detect natural estrogen but also be "fooled" into detecting environmental estrogens as well. This would be the ideal goal of designing these detection devices--that is to building artificial estrogen detection devices which can mimic actual estrogen receptors. Of course, if that is too difficult, then we will just have to build a receptor which can recognize specific environmental estrogens, but that would, of course, greatly limit the potential applications of our system. I think this would be the most important part of our project. Creating a good detection device would at least be an application by itself; creating the signal and destroying the chemicals would more just be parts that would need other components to become a useful tool. Anyway, look at the link I posted below on the BioBrick created by the University of Alberta to get an idea of an estrogen detector. Check out the link I posted below on a BioBrick which detects and reacts to environmental estrogens created by the University of Alberta for the 2008 iGEM competition
- Creation of Signal (likely GFP)
- Once the estrogen has been detected, the next phase of the project would involve sending out a useful signal which could inform people that environmental estrogen is present. Once the estrogen has been detected, the next phase of the project would involve sending out a useful signal which could inform people that environmental estrogen is present. The most obvious way of doing this would be to have cells glow green when they have detected estrogen, similar to the Imperial College's infector detector from 2007. Of course, if anyone can think of a better way of creating a signal that would allow people to know that estrogen-like particles are present in some kind of area, then post away.
- Destruction of Chemicals
What We Know
What We Don't Know (but need to know)
- Quorum Sensing
- Do we need to kill the cells after they have performed their task?
- An article about detecting infected catheters
- Toxin Alert: a company creating products to detect harmful bacteria in food
- The part we could use as an estrogen receptor
Ming Yan: We could perform protein engineering (such as protein shuffling) on the human estrogen receptor. After creating a library of different estrogen receptors, we could screen them for the ones with optimized detecting activity and greatest stability when incorporated into a manufactured product. Going through the Toxinalert website, it was mentioned that their product is printed on a plastic film that is incorporated into food packaging, such as the food wrap and sandwich/freezer bags. With that, I think that whatever receptor we develop, we need to somehow make it so that it could be attached to a certain surface or somehow incorporated into plastic.
- Joseph Lau 21:56, 30 March 2009 (EDT): Looking at the things that normally contain environmental estrogens (pesticides, lotions, other synthetic chemical compounds), I can't think of an easy way to implement the estrogen-detecting e. coli cells. To live, the e. coli would need substrate, which I presume people wouldn't want in their shampoo or lotion or whatever.
- Maybe if we develop it as a modular label or pill? Kind of like the silicon packets that you find in food, except this would be a packet that glows green if it's in the presence of estrogen. But again, it'd be hard to separate the actual product from our sensing unit.
- THEN AGAIN... we could just not worry about that part.
- (Chris)Estrogen Receptors are only expressed in Eukaryote cells? We will need the cDNA of the proteins and some of the other isoforms. Also we need to check whether or not the protein can be expressed in E.coli. Check PMID: 11162922. Someone should do a NCBI search through the protein database to see what stable forms exist.
Also, please try to avoid protein engineering approaches unless you can think of a good rational design method. Shuffling might take too long. Some things to consider.