Team:SJTU-BioX-Shanghai

Background of Our Team

Our team consists of 11 members, who are all junior students of Shanghai Jiao Tong University. Most of us came from School of Life Science and Biotechnology. We are working, living and studying like a whole family.

We were discussing our project and doing experiments in Bio-X institute of SJTU.

Description of Our Project

Membrane Workshop

- Cluster makes it faster; interaction alters the direction

Motivation:

1. There lacks compartment in prokaryotic cells, and thus engineered enzymes diffuse in the cytoplasm, which makes certain reactions proceed at a very low speed.

2. Divergent biochemical pathways commonly exist in all types of organisms, but it is extremely hard to artificially control and switch the directions of these reactions.

What to do:

We aim to attach enzymes involved in certain reactions to membrane proteins in order to fulfill goals stated below:

1. To accelerate reactions in certain biochemical pathway

2. To switch the biochemical pathway from one to the other through extracellular signal control

Our ultimate goal is to design a universal tool which functions as “engine” and “switch”. We master the membrane of E.coli and change it into an efficient workshop, where biochemical reactions are highly driven and well controlled. The “membrane workshop” project will solve common problems existing in bioengineering, i.e. the speed limit rooted in compartment-lacking prokaryotic cells and the lack of control over branched reactions.

1. Membrane Engine (Accelerator)

As there is no compartment in prokaryotic cells, enzymes involved in a biochemical pathway diffuse all over the cytoplasm. Intermediates generated from one enzyme cannot be passed efficiently to the next due to spatial obstacles. However, if we attach those enzymes to engineered membrane proteins which assemble together, the reactions are going to proceed much faster.

Why do we attach enzymes to interacting protein domains and ligands that assemble together?

– Interacting proteins fused with enzymes can decrease the distance which intermediates must travel between enzymes, improving reaction speed.

Why do we localize the enzymes to the membrane?

– Interaction of proteins can only be effective within a small distance. Membrane localization of the enzymes can integrate those engineered proteins to 2-dimensional scale, which would absolutely increase the possibility that potential interacting domains and ligands dimerize.

2. Membrane Switch

Now we have built a device that can speed up a biological pathway. Our next goal is to control the pathway better---- to switch the direction of certain reactions, as shown in figure 3.

Divergent biochemical pathways commonly exist in all types of organisms, and most of those reactions are stringently and internally controlled. However, it is extremely hard to artificially control and switch the directions of these reactions. Usually there are two different products produced in divergent reactions. Sometimes we want one product, and sometimes we want the other. Using our designed device, we can change the direction by introducing different extracellular signals.