Team:SJTU-BioX-Shanghai/Project

From 2012.igem.org

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(Introduction)
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Previous researchers have focused on building protein, RNA or DNA scaffold as constitutive assemblies carrying enzymes. They have  succeeded in increasing product yields. However, the amount of those scaffolds could be limited by its expression or copy level, leading to restriction on further acceleration. With ''Membrane Magic'', we made ''E.coli'' membrane into a huge scaffold accommodating enzymes without limitation of scaffold amount. Moreover, protein assembly on membrane could readily receive extracellular or intracellular signal, so the whole system becomes highly tunable.  
Previous researchers have focused on building protein, RNA or DNA scaffold as constitutive assemblies carrying enzymes. They have  succeeded in increasing product yields. However, the amount of those scaffolds could be limited by its expression or copy level, leading to restriction on further acceleration. With ''Membrane Magic'', we made ''E.coli'' membrane into a huge scaffold accommodating enzymes without limitation of scaffold amount. Moreover, protein assembly on membrane could readily receive extracellular or intracellular signal, so the whole system becomes highly tunable.  
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One of our devices, called ''Membrane Accelerator'', functions by localizing and organizing enzymes on membrane surface. ''E.coli'' inner membrane serves as a two-dimensional plane that can accommodate various protein assemblies linked with enzymes. Otherwise diffusing enzymes can form clusters on membrane through interacting protein domains and ligands. Enzyme clusters help substrates flow between enzymes, and  thus increase yields of sequential biological reactions. We not only applied the ''Membrane Accelerator'' into biosynthetic  pathway but also biodegradation pathway, which is proposed in application of ''Scaffold System'' for the first time.
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One of our devices, called ''Membrane Accelerator'', functions by localizing and organizing enzymes on membrane surface. ''E.coli'' inner membrane serves as a two-dimensional plane that can accommodate various protein assemblies linked with enzymes. Otherwise diffusing enzymes can form clusters on membrane through interacting protein domains and ligands. Enzyme clusters help substrates flow between enzymes, and  thus increase yields of sequential biological reactions. We not only applied the ''Membrane Accelerator'' into biosynthetic  pathway but also biodegradation pathway, which is proposed for the first time in synthetic biology. Previous researches on scaffold system all focused on biosynthesis.
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''Fig.1:'' Sketch of ''Membrane Accelerator''
''Fig.1:'' Sketch of ''Membrane Accelerator''
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Although some work has been done in reaction acceleration, artificially and dynamically controlling those reactions has always been a challenge. ''Membrane Rudder'' device, however, offers a novel method to control the direction of biochemical reactions through varieties of signals. We further combined the whole post-translational control system with genetic circuits by recruiting RNA aptamer and its corresponding binding protein. Thus RNA signal could also be recruited to dynamically control biochemical reaction.
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Although some work has been done in reaction acceleration, it has always been a challenge to artificially and dynamically control those reactions. Our ''Membrane Rudder'' device, however, offers a novel method to control the direction of biochemical reactions through varieties of signals. We further combined the whole post-translational control system with genetic circuits by recruiting RNA aptamer and its corresponding binding protein. Thus RNA signal could also be recruited to dynamically control biochemical reaction.
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Revision as of 08:55, 23 October 2012

Project Overview

Background Information:

Advance in molecular cloning technology has made it possible for mankind to entitle engineered organisms to different biochemical reactions. However, the speed of those enzymatic reactions is often limited because intermediates produced from upstream enzyme cannot be passed efficiently to downstream enzyme due to spatial obstacles. Thus, synthetic scaffold built to decrease distance between enzymes for speeding biochemical reactions is a hot topic with promising application prospect.

Moreover, although some progress has been made in fields of reaction acceleration, no one has before succeeded in dynamically controlling direction of the biochemical pathway.


Introduction

In this year, we expanded the definition of scaffold in synthetic biology and developed two universal devices called Membrane Accelerator and Membrane Rudder respectively. Together,they made Membrane Magic happen!

Previous researchers have focused on building protein, RNA or DNA scaffold as constitutive assemblies carrying enzymes. They have succeeded in increasing product yields. However, the amount of those scaffolds could be limited by its expression or copy level, leading to restriction on further acceleration. With Membrane Magic, we made E.coli membrane into a huge scaffold accommodating enzymes without limitation of scaffold amount. Moreover, protein assembly on membrane could readily receive extracellular or intracellular signal, so the whole system becomes highly tunable.

One of our devices, called Membrane Accelerator, functions by localizing and organizing enzymes on membrane surface. E.coli inner membrane serves as a two-dimensional plane that can accommodate various protein assemblies linked with enzymes. Otherwise diffusing enzymes can form clusters on membrane through interacting protein domains and ligands. Enzyme clusters help substrates flow between enzymes, and thus increase yields of sequential biological reactions. We not only applied the Membrane Accelerator into biosynthetic pathway but also biodegradation pathway, which is proposed for the first time in synthetic biology. Previous researches on scaffold system all focused on biosynthesis.

Fig.1: Sketch of Membrane Accelerator

Although some work has been done in reaction acceleration, it has always been a challenge to artificially and dynamically control those reactions. Our Membrane Rudder device, however, offers a novel method to control the direction of biochemical reactions through varieties of signals. We further combined the whole post-translational control system with genetic circuits by recruiting RNA aptamer and its corresponding binding protein. Thus RNA signal could also be recruited to dynamically control biochemical reaction.

Fig.2: Sketch of Membrane Rudder

Why MEMBRANE?

12SJTU Why membrane.jpg

Why do we choose membrane as our primary scaffold to assemble enzymes?

1. Priority to Exportation: Final products would be more readily to be exported to extracellular media if enzymes are localized to membrane.

2. Two-Dimensional Plane: Our project changes the dimension of traditional reaction space, making possible the assembling of various reactions on a two-dimensional plane, which has been proved to accelerate reaction more sharply than one-dimensional or discrete scaffold.

3. Tendency to Interaction: Previous study has developed discrete protein scaffolds which recruit enzymes diffusing all over cytoplasm. In our study, enzymes were anchored onto the membrane and become more likely to interact with each other.

4. Ability to Sense Signal: Membrane Scaffold provides a platform to receive environmental and internal signal. Thus reactions could be controlled through those signals.