Antarctica is one of the most extreme habitats on Earth. Temperatures close to the freezing point pose major challenges for organisms, as many biological processes slow down in the cold. Nevertheless, some fish species have successfully adapted to these conditions. A research team from Andrés Bello University in Chile has now investigated how Antarctic fish are able to maintain their vital metabolic processes even under extreme cold.
The study focused on the transport protein PepT1, which is responsible for the absorption of peptides and amino acids in the intestine. These substances are essential building blocks of proteins and play a central role in growth, energy production, and metabolism. In many organisms, this protein loses efficiency at low temperatures. In the Antarctic icefish Chionodraco hamatus, however, it remains active even under extreme conditions.
Using advanced molecular simulations, the researchers examined the structure and behavior of the protein at different temperatures. They found that Antarctic PepT1 possesses remarkable flexibility. This allows the protein to adjust its shape and continue transporting nutrients efficiently. In addition, the protein was shown to maintain its binding capacity across a wide temperature range, ensuring reliable nutrient uptake.
Another important finding was the discovery of a thermosensitive region within the protein that acts like a temperature sensor. It changes its structure depending on the surrounding temperature and helps stabilize the transporter’s function. The interaction between the protein and the cell membrane also plays a crucial role. This ensures that the membrane remains sufficiently flexible for the protein to perform its tasks effectively.
The results demonstrate that adaptation to extreme cold is based on the interplay of several mechanisms. The research provides valuable insights into the evolution of organisms in extreme environments and may contribute in the future to the development of resilient proteins for applications in medicine, biotechnology, and materials science.
Heiner Kubny, PolarJournal