Team:Imperial College London/Temporal Control/Thermoinduction

Thermoinduction means using a change in temperature to cause a biological change to the system. One way this can be done is by increasing temperatures of the system. Thermal denaturation will occur and this results in decreased binding efficiency of the substrate with the enzyme. Therefore a biological change will be induced.

Relevance to our project

We made use of thermoinduction in Module 3 – genome deletion, in our E.ncapsulator.

In short, thermoinduction is used to start genome deletion when sufficient drug protein of interest has been produced, and encapsulation is complete. Genome deletion then induced by manually raising the temperatures from 28°C to 42°C. This would cause de-repression of the pLambda promoter. Restriction enzymes DpnII and TaqI will be produced. They are the ones who carry out DNA restriction, and cause cell death.

In this case, we have used BBa_K098995 (Harvard 2008). This BioBrick consists of the heat sensitive cI857 with a strong promoter. This temperature sensitive cI857 protein repressor, has a significantly decreased binding efficiency with the cI promoter between 35°C to 42°C. Therefore when temperatures are increased, the cI protein repressor would have a decreased probability of binding with the cI promoter, due to thermal denaturation. We can now say that will be a de-repression at higher temperatures.