The human body is like a construction site where hundreds of thousands of different molecular nanomachines, called proteins, are simultaneously at work. Each one of these biomolecules, which are chains of amino acids essential to living organisms, perform a different biological function, often in synergy with other proteins. During their formation (the folding process) or in the performance of their biological functions, proteins change their shape in a very specific way. In many cases it is possible to conduct experiments that provide images of proteins at near atomic resolution, but only when they are in the stable and biologically active form. The dynamic processes associated with changes in shape are still largely unknown. Understanding these mechanisms and predicting the behavior of proteins is a fundamental step, for example, to develop advanced medical treatments for old and new diseases, from the most studied (like cancer and degenerative diseases) to emerging ones (Covid-19), to rare diseases.
Great strides have been made in recent decades in the study of processes involving structural changes in proteins, using computer simulations. Now, quantum computers are a powerful tool for carrying out even more precise and complete observations, as demonstrated by the study conducted by a group of physicists of the University of Trento that appeared in Physical Review Letters, one of the most prestigious physics journals that has been published by the American Physical Society since 1958.
"For the first time, we demonstrate that quantum computers can be used to understand at near atomic detail the functioning of biomolecules", explains Pietro Faccioli, author of the scientific article together with colleague Philipp Hauke and student Giovanni Mattiotti. Using this technology, the researchers of the Physics Department of the University of Trento have developed a method to compute changes in protein shape and trajectory. A breakthrough that has implications for molecular biology, pharmacology and nanotechnologies.
The fields of application are many. Identifying the mechanisms behind neurodegenerative processes in some proteins, for example, can help limit their proliferation. Understanding how a protein takes on a certain shape can open the way to use the nanomachines that nature has designed to cut, edit or block damaged or defective genes.
"We reformulated the mathematical problem underlying the predictions of structure changes as an optimization problem", underlines Pietro Faccioli. "Quantum computers are particularly suitable for solving optimization problems because they exploit a fascinating phenomenon known as quantum delocalization, which is only found in the microscopic world," adds Philipp Hauke.
About the article
The article "Dominant Reaction Pathways by Quantum Computing" was written for the scientific journal "Physical Review Letters" by Giovanni Mattiotti, Philipp Hauke and Pietro Faccioli. Giovanni Mattiotti is now a doctoral student at the Physics Department of the University of Trento, while Philipp Hauke and Pietro Faccioli are associate professors at the same department.