Our team collaborated with LZU-HS-China-A and LZU-HS-China-C in many aspects
throughout the season.
Team introduction
To begin with, let’s introduce ourselves briefly.
Our team BFSU-ICUnited, is a high-school team united from many regions in China.
ICUnited has initiated attempts to tackle one of the most massive environmental issues by offering a
novel method for BPA detection which features the use of electrochemical enzyme biosensors. Cell
surface display is a crucial section involved in our project since it can significantly reduce the
limitations including reaction rates caused by enzyme activity loss.
LZU-HS-China C's project focused on preventing the inherent hazards of antibiotic
release due to the improper disposal of polluted wastes in the poultry business, namely the
potential of superbugs. They went on to design a whole-cell biocatalyst aimed at degrading
antibiotic residuals in animal feces. Their team needed the cell surface display technique to
improve their otherwise inefficient antibiotic degradation rate.
LZU-HS-China-A found that a large amount of shrimp and crab shell waste is generated
every year, and the team believes that this waste can better play its role. LZU-HS-China-A attempts
to convert chitosan into chitosan oligosaccharides by cell surface display.
Research and selection based on anchor protein used in cell
surface display
Firstly, and most importantly, since we both use cell surface display
technology in our projects, we can help each other technically. In the earlier phase, the problem we
faced was choosing a proper anchor protein, which is an essential protein used in cell surface display
technology. This is a critical section of the projects for our three teams, but we have no idea which
kind of protein can be used, so during our first online meeting, we set up a detailed plan for our
projects’ future progress.
Evidence of online meeting
We initially did some research based on the properties required for anchor
proteins. By exchanging useful papers, then giving presentations to obtain a clearer understanding of
anchor protein, we get the following information:
-Properties required for anchor proteins
1. Having signal peptide sequences or transport signals that guide the fusion protein across the
cell membrane
2. Can guide the fusion protein to specific sites on the cell surface
3. Having stable anchor elements that can be recognized at specific sites on the cell surface, so
that the fusion protein can be immobilized on the cell surface
4. Fusion with foreign proteins will not change its stability, and it is uneasily to be broken down
by proteases in or outside the cell
In addition, we found out the consequences of choosing an unsuitable anchor protein:
1. The structure of anchor protein and passenger protein is easy to affect each other, interferes
with their correct folding, and reduces the activity of passenger protein
2. Different transporter proteins will affect the physiological function of the recipient bacteria
(growth instability, etc.)
After filtering these required properties, we obtained several satisfied anchor proteins:
Lipoprotein, S-layer protein and INP.
From them, also followed the instructions given by our advisors, we eventually decided to
use ice-nucleation protein, since its advantages in cell surface display technology:
-Pros of INP
1. Stably expressed in a large variety of species of host cells
2. Uneasily to be broken down by proteases in or outside the cell
3. High efficiency of displaying on the surface of the host cell
4. Repeating structures can be cut without influencing the functions, which can be advantageous
when carrying passenger proteins with larger molecular weights
5. No auxiliary proteins are required
-Cell surface display mechanism
Ice-nucleation protein is frequently used in cell surface anchors for protein display
in Gram-Negative bacteria. The bacterial surface display has been widely applied in scientific
research and the science industry. Various functional peptides, recombinant vaccines, and catalytic
enzymes could be displayed on bacterial surfaces through appropriate surface anchors, which
facilitated their further engineering and applications for certain purposes.
The hydrophobicity of the nitrogen terminal is fused with the phospholipid bimolecular
membrane to fix the linked enzyme on the cell membrane, and the hydrophilicity of the carbon
terminal is exposed outside the cell membrane to connect with the acting enzyme so that the enzyme
can be effectively expressed outside the cell membrane.
Evidence of discussion and presentation
In the end, by experiments, the efficacious result proves that our
discussion and collaboration are successful and vital. During this experience, collaboration allowed us
to work more effectively by urging and encouraging each other. Also, we were able to interact with our
ideas and brainstorm together, which is particularly beneficial for our projects’ promotion.
Projects popularization
During the middle stage of iGEM, another aspect of collaborating is publicizing our
projects. In order to obtain more valid data for integrated human practice, we had to popularize our
questionnaire and project introduction. However, due to the fact that these specialized topics are
not that straightforward for people to understand, our WeChat official accounts have limited figures
for pageviews, which is not conducive for us to appeal to more people, and raise their awareness of
environmental issues (etc.) involved in our projects.
Thus, after holding an online meeting, we decided to let more people know us by
promoting each other’s projects. We achieved this goal in two methods. Firstly, we summarized
others’ project descriptions, make them less complicated, and published them in our account. During
the discussion, we thought simplifying is a useful way to make our articles more readable. Plus,
although we only have a small number of followers, the sum of followers of our three teams is still
relatively sizable.
We can see remarkable progress in pageviews after collaboration, and we firmly believe that
by our influence, more people are willing to consider these crucial issues. This significant increase
also reveals our efficient collaboration, when facing a problem, that we can achieve our targets using a
simple but useful method.
Information collection and preparation for synthetic biology
education
After some time, when preparing for the section on education, we cooperated
again for better performance on what we can contribute to the public and synthetic biology. We firstly
divided the workload via online meetings, in which our team was in charge of presenting, LZU-HS-China-A
for slides and poster creation, also online lecture, and LZU-HS-China-C for related content preparation.
This work division was based on our advantages of owning a proper venue for education, outstanding
design skills from LZU-HS-China-A, and LZU-HS-China-C who are good at information collecting.
Evidence of giving out posters and presenting
We accomplished this section together, not only for better effectiveness but
also to allow our three teams to bring out our diverse strengths, to make a greater performance.
Moreover, more audiences are involved because we separately propagandize the lectures. These advantages
can be only shown between team collaboration, therefore we are able to achieve a better job.
Conclusion
Our three teams mainly collaborated in three aspects throughout the season,
consisting of selecting INP, project popularization, and education. For us, the partnership is much more
than “for a less workload”, or “best showing our strengths”. Without doubts, these are prominent traits
of cooperation, besides, our cooperation and communication skills have been significantly enhanced.
However, after facing uncountable difficulties as trustworthy allies, and also as high school students,
our abilities to get over hardships have incredibly improved. In addition, most importantly, we are very
honored to encounter such more friends who are also fond of the field of synthetic biology, and we are
willing to contribute more to synthetic biology in the future.
References
1. Li Qixi. (2009) Construction of bacterial cell surface display system using ice crystal nuclear
protein and its application. Huazhong Agricultural University.
2. Zhang, Z. et al. (2016) Surface immobilization of human arginase-1 with an engineered ice nucleation
protein display system in E. coli, PloS one. Public Library of Science.
