The physical reality of proteins

"Everything is physics," says Dr. Roi Bek-Barkai. In his laboratory at the Center for Nanotechnology and Nanoscience he built one of the most sophisticated X-ray scattering systems in the world

"Everything is physics," says Dr. Roi Bek-Barkai. In his laboratory at the Center for Nanotechnology and Nanoscience he built one of the most sophisticated X-ray scattering systems in the world. The goal: to deal with a task that was previously considered impossible: finding simple physical formulas to describe a huge variety of biological phenomena and structures / the infrastructure of physical knowledge is already used today to understand mechanisms related to various diseases, and in the future will even serve as a basis for developing drugs or nanometer drug carriers

"The world of biology is a great challenge for physicists," says Dr. Beck-Barkai from the School of Physics and Astronomy. "The tools of physics were originally defined for relatively simple molecules, whereas biological structures, primarily proteins, are large, complex and extremely diverse. In my lab we are facing a task that was previously considered impossible: finding simple and elegant physical formulas, with a minimal number of parameters, that would describe a huge variety of properties, phenomena and biological structures. To this end, we operate in the area of ​​the seam between biology and physics, in combination with materials engineering, chemistry and medicine." Accordingly, Dr. Beck-Barkai's research group is multidisciplinary, and works in collaboration with many researchers on campus, including Dr. Dan Parr and Dr. Yoel Hirsch from the Faculty of Life Sciences, Dr. Yael Ruichman from the Department of Chemistry and Dr. Uri Nevo from the Faculty of Engineering.

From Dr. Beck-Barkai's point of view, "everything is physics". Physical forces and laws are responsible for the movements and interactions of all systems in the universe, from the level of galaxies to the level of atoms. And so, in order to deeply understand the properties and behavior of biological materials, he chose to examine the physical forces acting within and between them, at the nanometer level. "The nanoscale world in biology is characterized by the organization, often spontaneous, into clusters consisting of a large number of biological molecules, such as proteins, fatty acids and genetic material," he explains. "In my lab we try to find out what the physical mechanisms and intermolecular forces are responsible for the various phenomena: how the molecules 'talk' to each other, and how exactly they organize and create new structures together. We measure, quantify and map the forces, locate the dominant mechanisms, and try to formulate systems of physical laws that will describe the behavior of materials and explain the biological processes."

A complex technological challenge

In order to examine the behavior of tiny biological molecules, Dr. Beck-Barkai is required, first of all, to face a complex technological challenge: on the one hand, an optical microscope is not enough to observe such tiny structures; On the other hand, in order to use tools with nanometer resolution, the researcher must drastically change the environment of the biological material, and in this transition some of the original properties of the material are lost. Therefore, the researchers work with an advanced method: measuring the scattering of X-rays at small angles, which makes it possible to observe the nanoscale clusters in a liquid that simulates their natural environment in the living cell. The X-ray scattering system designed and built by Dr. Beck-Barkai in his laboratory at Tel Aviv University is one of the most sophisticated and advanced of its kind in the world.

Using the innovative technology, the research team examines the forces that affect the self-organization of structures and nanometric clusters of proteins, sugars and genetic material. The research focuses on the physics of unfolded proteins (Intrinsically Disordered Proteins), a field that has gained a lot of momentum in the last decade all over the world. "Most of the known proteins are characterized by a folding process responsible for their functionality," explains Dr. Beck-Barkai, "but in recent years it has become clear that about half of the proteins in the body are also characterized by functional regions that are not folded. The activity of these proteins arouses great interest, and we aim to develop convenient characterization methods for them."

The infrastructure of physical knowledge that the researchers are building is already used today to understand clusters of biological molecules, related to various diseases that develop in the body, or, alternatively, may be used in the future as a basis for developing drugs and nanometer drug carriers. "A basic physical understanding, at the nanometer level, of the biological mechanisms and the failures that occur in them, will allow in the future to identify the most primary cause of the disease, and to provide it with effective and targeted treatment, which will be adapted to each patient personally," predicts Dr. Beck-Barkai.

Ger Tel Aviv University, who specialized in solid state physics, with a focus on superconductors and physical phenomena at low temperatures and high strength magnetic fields. As a research fellow of the prestigious Human Frontier Science Program, he began to study biological materials at the University of California, Santa Barbara, with the aim of understanding the physical properties that make them behave in the way that characterizes them. In 2010, he returned to Tel Aviv University as part of the program to encourage the return of Israeli scientists, and established an advanced biophysics laboratory.