By summerstudent Christina Papaefthymiou>
When I applied for the HZB Summer Student Program in December 2023, I had no idea what was to come. Knowing that finding accommodation in Berlin is not an easy task, I felt very lucky to secure an apartment four months before my arrival. Deep inside, I knew that once I stepped foot in Berlin, everything would fall into place and my fears would go away. And so it happened. The only unexpected condition when I arrived was the warm weather….
My experience in the MX team
During my stay in Berlin, my mind is mostly focused on my project within the Macromolecular Crystallography (MX) team. On the first day I joined a group meeting, where everyone welcomed me, and they encouraged me to ask for their help and expertise whenever I needed it. I am grateful to be surrounded by people who are willing to teach me and guide me through the process.
The BioLab, which is the MX team’s lab, is located a five-minute walk away from BESSY and this is my main workspace. The first time I entered the BioLab I was amazed by the experimental rooms, being so well equipped and organized. There are so many machines and tools for many kinds of experiments focusing on studying proteins. It feels like the right place for me to learn lots of new techniques that I have not performed before.
My project on a PET-degrading enzyme
The goal of my project is to study the structure of a protein, specifically an enzyme, that can degrade PET plastic. To study this enzyme, I first have to produce it myself in the lab, by expressing and purifying it. This is accomplished using bacteria as host cells, something I had never done before because I was used to working on commercially available pharmaceutical proteins and peptides.
The Challenge
The challenge in this process is that growing the bacteria and inducing them to express the protein takes many weeks and a series of protocols. The experiments involving bacteria have a specific time schedule that one must follow, so I have to adapt to their rhythm, not mine. Dealing with live organisms like bacteria requires lots of caution to avoid contamination and to provide the ideal conditions for growth, or else protein production will fail. After the induction of protein expression, the next step is lysing of the bacteria to isolate the protein of interest, by purifying it from the cellular debris. This process also involves many steps, and I have to be very careful in handling the protein solution to avoid destroying the protein molecules.
After a long day
Every day, I learn something new, and my lab-book is getting filled with a great variety of protocols. To prevent losing track of my experiments I must write everything down at the end of each day, or else I might get lost in all the protocols. Even though some days were longer than others, I always return home with a smile on my face, feeling satisfied that I have tackled a new challenge. For example, one day I returned home at 21.00, it was the end of the week, and I was very tired, but it was the first time that some amount of my protein was produced, and even though the yield was a little low, I could not be any happier.
The goal: Recycling PET
Since there is inadequate end-of-life management of plastic waste, this study of PET-degrading enzymes can contribute to a more sustainable way of recycling PET plastic waste that aligns with circular economy. The enzymatic degradation of PET polymers produces monomers which are valued chemicals for the resynthesis of the polymer, leading to the decrease in humanity’s carbon footprint by producing less new plastic and using the amount that is already available and fully recycled. As I am a sustainability advocate myself, the goal of this project motivates me to work even harder, hoping this might have a positive outcome in the future.