Ultra-short X-rays to understand complex biological processes

Mohammed Shaban

Although scientists can understand the basic mechanism of photosynthesis, many of its important details remain vague. They occur in a very short period of time, which makes them difficult to search and scrutinize. This requires the development of existing technologies to provide additional dimensions that enable us to better understand their details.

So in a new study published in the journal Nature Communications on Nov. 4, Petra Fromm and Nadia Zashpin - from the Center for Biosynthesis at the College of Molecular Sciences and the Physics Department at Arizona State University - used the ultra-short-ray impulses of Oxville. In Hamburg, Germany to study the structure of the first optical system (PSI) one of the two systems of photosynthesis.

Serial crystal imaging
Using Oxville's new electron accelerator, researchers produced pulses of X-rays nine thousand times faster than their counterparts in other accelerators. This enabled researchers to shoot molecular films of rapidly occurring biological processes.

So Oxfell's accelerator "is an important stage in the development of crystallographic imaging in very accurate femtosecond times," Zachpin said.

Christopher Gissrell, senior researcher of the study, adds that this revolutionary technique "has allowed us to obtain serial data in very small times, which makes it very important for those interested in studying the relationship of the form of enzymes and their function. This is confirmed by our success in obtaining the structure of one of the most Complex proteins. "

"It is exciting to see the fruits of this hard work," said Jessie Co, senior co-researcher.

Revolutionary applications
Through its first photosynthesis system, photosynthesis can convert solar energy into chemical energy, which is a natural asset.

Scientists have used ultra-short-ray pulses to study the first optical system, which consists of 36 types of proteins and 381 cofactors, including 288 dyes of green chlorophyll pigments that absorb light.

These proteins were extracted from cyanobacteria, then carefully separated to retain their active form in their natural state, and then converted into a crystalline state.

These proteins were then placed in the same direction as the X-ray pathway produced by the acceleration of electrons at a speed close to the speed of light. This has led to the dispersion of X-rays as they pass different protein atoms, producing patterns of diffraction, which enabled scientists to determine the structure of the protein with a precision of 2.9 milligrams.

It also allowed scientists to take pictures of the atomic structure of the protein in a naturally similar shape, and because the x-ray pulses produced by Oxville accelerators have a very short lifespan, they take very fast images of the protein before any synthesis occurs.

“This work is very important,” says Fromm. How to attack cancer drugs for fresh proteins. "

So revealing the secrets of photosynthesis could enable us to improve agriculture and help develop a new generation of solar storage systems.

Future prospects
Proteins in cell membranes, such as those of the first optical system, are essential for all vital processes such as respiration, nerve function and absorption. Drug companies target more than 60% of other cellular proteins.

Despite their importance, we know less than 1% of their structural structures because of the difficulty of separating them and forming the necessary crystals to study. Thus, significant advances in the imaging of these crystals using the femtosecond sequencing mechanism may enable us to study many of these membrane proteins in the future.