The human fertilization starter simulated on the supercomputer - Biotech

For the first time it is possible to see the starter of human fertilization in action: highly realistic simulations created thanks to a supercomputer show the complex molecular interactions that allow the fusion between egg and sperm, which until now were impossible to observe directly under the microscope or by crystallography.

The result is published in Scientific Reports by researchers at the Federal Institute of Technology in Zurich, in a study that lays the foundations for new non-hormonal contraceptives and new therapies against infertility.

Thanks to the Piz Daint supercomputer of the Swiss National Supercomputing Center (CSCS), researchers led by Viola Vogel simulated the behavior of the two key fertilization proteins: Juno, located on the outer membrane of the egg, and Izumo1, on the surface of the sperm.

To recreate a realistic model, the proteins were simulated in an aqueous solution: the presence of water molecules in fact changes the way in which the two proteins bind to each other and, in some cases, even their very functioning.

The team thus obtained simulations lasting 200 nanoseconds each, in which it is observed that the Juno-Izumo1 protein complex is stabilized by more than 30 bonds, each of which lasts less than 50 nanoseconds.

Instead, the zinc ions destabilize the complex: when they are present, the Izumo1 protein takes on a boomerang structure and is unable to stably bind Juno.

According to the researchers, this could be one reason why fertilized eggs release a 'storm' of zinc to prevent a second sperm from getting inside.

Thanks to the supercomputer, researchers have also managed to reveal another aspect of fertilization that has not yet been fully clarified: the role of folates and their synthetic equivalent, folic acid, often recommended to women in the early stages of pregnancy to promote correct development of the fetus.

Molecular dynamics simulations show that folate binds to Juno, as previously hypothesized, but only when the protein is in turn bound to Izumo1.

Reproduction reserved © Copyright ANSA