The great advantage of using neutron scattering within the Life Sciences is not only the greater sensitivity towards hydrogen as compared to using X-rays as probe instead, but more importantly the ability to distinguish hydrogen from its heavier isotope deuterium. This property enables highlighting different parts within a molecule or a molecular complex, and has been widely exploited in the past to study basically all types of biological molecules. However, the availability of deuterated compounds has always limited our capacity to design experiments. Even though there are a handful of facilities in the world working both with chemical and biological deuteration, more work is needed to expand the range of deuterated compounds.
We have teamed up with the Deuteration Lab at the Institute Laue Langevin (ILL) to produce deuterated cholesterol so that it is invisible in D2O. Perdeuteration of lipids can be achieved by growing bugs in D2O medium and feeding them with D2O based C-sources. Here, we played with the food of the bugs to achieve a partially deuterated cholesterol that is rendered invisible when prepared in D2O based solutions (matchout cholesterol). This matchout cholesterol was used to determine its location in lipid bilayers of various kinds, and can now be used by the community to better design experiments, as for example in our research to understand the lipid exchange by lipoproteins – the fat carriers in the body.
Mimics of biological membranes made of deuterated lipids and cholesterol have been used to study - by neutron reflection - the capacity to exchange fats by either the good or bad cholesterol purified from healthy patients. The data shows interesting trends, and is now being prepared for publication and will show the capacity. Similar methodologies are planned for other fats relevant to the diet.
This work resulted from a collaboration between the Department of Biomedical Sciences at Malmö University, the Life Sciences Group at the ILL, and the Institute of Molecular Biotechnology at Graz University of Technology. This project is funded by the Swedish Research Council and a PhD studentship of the Institute Laue Langevin. Experiments were performed at ILL and the ISIS neutron and muon source. If you are interested to get access to matchout cholesterol please contact Dr. Michael Haertlein at the ILL.
Further information: Waldie, S., Moulin, M., Porcar, L. et al Sci Rep, 2019