* My name is ###, and I am a ### majoring in ###. I am taking BME 494 because ###. An interesting fact about me is that ###.
* My name is Jennifer Sherwood, and I am a senior majoring in chemical engineering. I am taking BME 494 because I am interested in learning new ways to engineer biology. An interesting fact about me is that I enjoy playing golf and creating stained glass lamps in my spare time.
By modifying the input and output for the Lac switch, it may be possible to produce materials such as plastics. The switch could be triggered by another environmental factor other than [IPTG], and instead of producing GFP, more useful materials like plastic could be an output. Currently, production of plastics is a very energy intensive process, and by using bacteria for the production, we can save energy and limit waste into the environment.
The IPTG-input/fluorescent protein-output is proof of concept for the production of synthetic materials such as plastic being created by bacteria. In the original project, a synthetic compound was utilized to trigger the metabolic pathway for the degradation of lactose. Using synthetic biology, we can splice together different genetic features to create an entirely new metabolic response. We can find a promoter that responds to a different input. In the natural Lac-operon, the cell produces proteins for the breakdown of lactose. We modified the natural process by initiating the production of GFP instead of the functional proteins found in the original process. It seems, that if we are able to control our protein output, we can produce synthetic products as well.
Background
Diagram of Lac operon and how it functions without lactose present (top) and with lactose present (bottom)
The natural Lac-operon has 2 controls that tightly regulates the production of the proteins necessary for the breakdown of lactose. In the presence of glucose, the Lac Operon inhibits the production of those proteins. When glucose is present, the lac repressor is bound to the operator, prohibiting the transcription of the proteins. In the presence of lactose, lactose is able to bind to the lac repressor initiating a conformation change in the repressor protein, causing it to release and allow for transcription. This, however, is not the only control in place. It is incredibly energy intensive to produce the proteins necessary for the breakdown of lactose, so when there is glucose present, the glucose will be metabolized first, even with some lactose present. This is accomplished by the presence of a second regulatory device, cyclic AMP (cAMP). cAMP is present only when there are very low levels of glucose found in the environment. cAMP serves as an activator and binds to RNA polymerase allowing for transcription of the output proteins.
In the synthetic [IPTG] induced Lac-operon, IPTG serves the same function as lactose, it binds to the repressor causing a conformational change, allowing for transcription of proteins. In the natural Lac-Operon, the proteins were functional, and necessary for the breakdown of lactose. In our synthetic system, green fluorescent protein is produced instead. This protein serves as an indicator, allowing for visual verification that the lac switch is operational.
Design: Our genetic circuit
OUR GENE SWITCH:
AND gate Gene Switch: Both [IPTG] AND [Low Glucose Levels] conditions must be met for GFP production
Building: Assembly Scheme
Testing: Modeling and GFP Imaging
A LAC SWITCH MODEL
We used a previously published synthetic switch, developed by Ceroni et al., to understand how our system could potentially be modeled and simulated.
AN INTERACTIVE MODEL
We used a model of the natural Lac operon to understand how changing the parameter values changes the behavior of the system.
COLLECTING IMPERICAL VALUES TO IMPROVE THE MODEL
We explored how one technique, imaging via microscopy could be used to determine the production rate of an output protein, in this case GFP in yeast, could be used to determine a "real" value for maximum GFP production rate under our own laboratory conditions.
Ideally, the GFP production rate measured by this method could be entered as a value for [which parameter] in the Ceroni et al. model.
Human Practices
Danger of Chemicals in Farmlands
Our Team
Your Name
My name is Jennifer Sherwood, and I am a senior majoring in chemical engineering. I am taking BME 494 because I am interested in learning new ways to engineer biology. An interesting fact about me is that I enjoy playing golf and creating stained glass lamps in my spare time.
Your Name
My name is ###, and I am a ### majoring in ###. I am taking BME 494 because ###. An interesting fact about me is that ###.
Your Name
My name is ###, and I am a ### majoring in ###. I am taking BME 494 because ###. An interesting fact about me is that ###.
