Synthetic biology is a field at the cross-section of biology, chemics, engineering, and computer science, therefore providing a unique opportunity for interdisciplinary collaboration. Its goal is to engineer biological systems to solve some of the most urgent problems that the world currently faces. It uses engineering principles such as the Design, Build, Test, Learn cycle to achieve success in building something useful.
iGEM (International Genetically Engineered Machine) is an annual international competition which was founded by the MIT (Massachusetts Institute of Technology) in Boston, USA in 2003. It focuses on solving pressing local and world-wide problems through the application of synthetic biology. In addition to interdisciplinary collaboration, the focus also lays on reaching out and educating the public. What started as a small competition involving only a handful of teams has developed into a world-renowned event, each year involving hundreds of universities from countries all over the world. Since 2003, iGEM has managed to bring together more than 30.000 young and ambitious people from more than 45 countries, contributing to scientific and intercultural exchange.
For the duration of the competition, the iGEM team Tuebingen will represent the University of Tuebingen as well as the faculty of science, the faculty of medicine, and the faculty of humanities on multiple occasions such as public events, discussion rounds or conferences on an international level. The iGEM competition will close with a congress, the Giant Jamboree. Due to the ongoing pandemic, it is not yet clear if the Giant Jamboree is going to be in person, but it is planned to take place in Paris. Team Tuebingen itself participates since 2011, successfully representing the University of Tuebingen and has won several medals over the past years.
Antibiotic resistance poses a major threat to global health. Through the use and misuse of antibiotics, many pathogenic bacteria have evolved a resistance against them. Consequently, today there are many diseases for which no effective antibiotics exist. This leads to increased mortality rates and higher medical costs worldwide.
A possible alternative to antibiotics are antimicrobial peptides , short AMPs. These naturally occur in humans, other animals and plants as a part of the innate immune response. AMPs are short proteins, which can act against bacteria, viruses, fungi and even cancer cells. They function by targeting the bacteria’s cell membrane, as well as multiple other targets. Additionally, many AMPs act by stimulating an immune response. Because of this mode of action, resistances against AMPs are less likely to occur than against antibiotics. However, most AMPs are relatively unstable limiting their therapeutic application.
In our project, we want to develop a fast expression and testing platform for stabilized AMPs , grafted into cyclotide scaffolds.
Cyclotides are cyclic peptides with a knotted structure formed by three disulfide bonds. This structure is responsible for their high stability towards heat, chemicals and proteases. The amino acid sequences in between the cyclotide’s cysteine residues are called loops. These are highly variable in sequence and can be replaced with other peptides to combine bioactivity of these peptides and stability of the cyclotide.
As an example, we want to graft the peptide KR-12, which is the antibacterial fragment of the human AMP cathelicidin. KR-12 will be grafted one or multiple times into different loops of the cyclotide McoTI-II. This cyclotide does not possess any antibacterial activity by itself. Therefore, the success of the different grafting approaches can be observed.
At first, we design different grafted cyclotide constructs. Their structure is modeled to make a theoretical prediction about their fold and conservation of the AMP’s bioactivity.
The designed sequences are then complemented to ensure their correct expression in plants later on in the project. Molecular cloning techniques in Escherichia coli are used to finally yield an expression vector. Besides the cyclotide sequence, this vector also contains a sequence encoding an enzyme needed for cyclotide maturation in plants (AEP).
Next, Agrobacterium is transformed with the expression vector. Agrobacteria are plant pathogens and are commonly used in biotechnology to insert DNA vectors into plant cells.
To express the grafted cyclotides, leafs of Nicotiana benthamiana (tobacco) plants are infiltrated with the transformed agrobacteria. Agrobacteria are infecting the plant cells with the expression vector, thereby equipping plant cells with the genetic blueprint to express the potential cyclotide peptides. Success of the infiltration can be observed by a co-expressed fluorescent reporter gene.
The expressed grafted cyclotides are isolated and purified from tobacco leafs and used for further characterization experiments.
Finally, to test the antibacterial properties of the grafted AMPs, activity tests are performed. This is done with both gram-negative and gram-positive bacteria. We are also collaborating with other iGEM teams to test our obtained constructs on different bacterial strains. Additionally, structure and mode of action of the antibacterial peptides can be predicted with molecular dynamics modeling .
We are the iGEM-Team Tübingen 2021, a group of 16 students spanning diverse fields from biochemistry, bioinformatics, biology through mathematics, up to rhetoric and media studies. With our diverse and interdisciplinary team, we plan to pursue an interesting and forward-looking research project with local and global relevance. The expertise of our competent subteams and past experiences from former projects combined with great motivation and the support of research groups as well as companies will help us to achieve our goal of a successful project. Thereby, the safety of genetically modified systems and their risk-free use in environmental, agricultural, or clinical applications is of great importance for us. With this year’s project we do not only aim at winning one of the prices at the ‘Giant Jamboree’-conference in October, but also strive to contribute to the progress and development in synthetic biology.
Having fun while doing our photo shoot
Tübingen's beautiful historic city center
The Morgenstelle, home of the natural sciences in Tübingen
Where the magic will happen: Our lab space
If you want to discover Tübingen, you need to go by bike
The iGEM Team Tübingen is an independent research group consisting of highly motivated and dedicated students from different disciplines, who independently design, plan and execute a scientific project. The project mainly aims to find solutions to current and future problems with the help of synthetic biology.
In addition, the iGEM competition offers students the opportunity to take personal responsibility, to pursue their own ideas and to acquire extensive knowledge not only in the subject area, but also in the following fields such as project organization, implementation, presentation, financing and public relations.
Participation in iGEM fosters the development of multifaceted skills that students acquire, making them stand out from the crowd and qualifying them excellently for the future working life.
The goal of the international iGEM competition is not only to solve current and serious problems using synthetic biology, but also to facilitate an international and interdisciplinary exchange between different students and universities. This promotes both knowledge and cultural exchange and enriches our community. Networking is an essential part of iGEM, establishing contacts between young researchers, professors and companies. Future collaborations can also benefit from this. In the past years numerous iGEM projects could be realized, some of which were further improved and optimized in the form of a start-up even after the competition.
The successful realization of an iGEM project is only possible through support in different areas. In order to realize our vision of a project and to expand the field of synthetic biology we need your help. Through financial or material support of the iGEM team, you as a company can already establish contact with highly motivated young researchers. In addition, we offer you a representation platform towards the public on our website, as well as in our presentations, social networks and more.