Researchers Sebastian Busch, Christoph Smuda, Luis Carlos Pardo and Tobias Unruh from the Universitat Politècnica de Catalunya (UPC) have discovered, using neutron spectroscopy techniques, that the molecules of a cell membrane do not move at random as previously believed, but rather in a flowing motion as suggested by various computer simulations. The discovery has a major impact on the regeneration of cell membranes and the biological mechanisms that involve membrane proteins. Their research is published in the Journal of the American Chemical Society (doi: 10.1021/ja907581s).

Cell membranes consists of a phospholipid membrane with amphipathic molecules that can repel and absorb water. This property enables them to self-organise into cell walls. The membrane also has a surprising ability to regenerate itself. According to Luis Carlos Pardo, a researcher at the Department of Physics and Nuclear Engineering of the UPC, “although the molecules that form the membrane are huge in relative terms, they have the uncanny ability to move and this is precisely what is responsible for the self-healing process. Imagine the bricks of a house being able to rebuild a broken wall”.

The research team of the UPC’s Materials Characterisation Group has devised a Bayesian analysis method (fitting algorithm for Bayesian analysis of data, FABADA) that has refuted the idea that membrane molecules move chaotically by diffusion. Instead, the team has discovered that they form currents that run through the cell membranes like a river. “This means that their small-scale mobility is greater than previously thought”, says Professor Pardo, a member of the team at the UPC’s Nanoengineering Research Center.

Phospholipid cell membranes are a very interesting area of research due to their natural abundance (every human body contains several square kilometres) and their pharmaceutical applications.