Discovery: Water plays an essential role in collagen assembly

ENGINEERINGNET.BE – About one-third of the proteins found in the human body are collagen. It ensures the mechanical integrity of all human connective tissues.

Since collagen is formed in the aqueous environment of human cells, it stands to reason that water plays a crucial role in its assembly.

However, this link has not been seriously investigated, according to Dr. Giulia Gobertoni of the University of Amsterdam in the Netherlands. That is why she, together with her colleague Prof. Dr. Sander Watersen and Prof. Dr. Gijsi Koenderinck from Delft University, decided to replace water with the heavier double molecule D2O.

This molecule contains deuterium instead of hydrogen atoms. The only difference is that deuterium has an extra neutron in its nucleus.

D2O is the natural alternative to regular water. But when it interacts with proteins, D2O is less effective than H2O. This is because the mutual bonds between D2O molecules are stronger than those of H2O molecules. This weakens the interaction with proteins such as collagen.

Their research showed that the use of heavy water can accelerate collagen synthesis by up to ten times, resulting in a less uniform, weaker and less stable network of collagen fibers.

The explanation is that with less interaction with heavy water, it is easier for the collagen protein to get rid of D2O molecules and reorganize itself.

This accelerates collagen network formation, but also results in a less than optimal collagen network. Water thus acts as a kind of mediator between collagen molecules, slowing down their aggregation and thus ensuring the function of living tissue.

This discovery provides opportunities to make new collagen-based materials. In addition, macroscopic properties may be modifiable by slight variations in solvent composition, without major changes to the chemical composition of the molecular building blocks.

Future research could also examine the role of water in the assembly of other proteins that also assemble into larger structures. Gobertoni will study how defects in collagen proteins affect interaction with water, and what role this plays in collagen diseases.

Partners in this research include the Max Planck Institute for Polymer Research in Germany and the Institute of Science and Technology in Austria.