Team:Valencia Biocampus/Orthogonality

Do biobricks behave independently when cotransformed in a cell? In other words, can we consider them to be orthogonal? Orthogonality is a mathematical concept that refers to the independence of behavior. Translating this concept into the biological realm, two constructions can be considered orthogonal when they only interact at specific and predictable interphases and do not disturb each other. This is a desirable feature of Biobricks if one wants to build synthetic circuits with predictable and robust behaviors.

To study this pillar of synthetic biology we are analyzing different combinations of Biobricks in cotransformed cells. That way, we can study the expression of pairs of Biobricks and compare them with simple transformations, and therefore determine whether the presence of two constructions in the same cell affects their behavior. In order to do so, we will measure the output of each Biobrick (i.e. fluorescense) in both the cotransformants and the controls.

We are going to study three combinations, taking in to account that each pair of biobricks is controlled by the same promoter and only differs in the protein expressed and the antibiotic resistance:

• Constitutive promoter I (strong) – GFP & Constitutive promoter I (strong) – RFP
• Constitutive promoter II (less strong) – GFP & Constitutive promoter I (strong) – RFP
• Ptrc – lacZ & Ptrc – luciferase

Besides individually transformed cells, we will use a control consisting of cotransformed cells with a Biobrick-bearing plasmid and an empty one.

We are currently working on all this. But we have another, very ambitious experiment. We plan to determine the effect of the production of a single heterologous protein on the proteomic architecture of the host cell. For this endeavor, we just submitted our samples for a proteomic quantification.