Scientists discover possible mechanism for creating 'handedness' in biological molecules

Dec 01, 2008
1s XPS spectrum of (R)-2-butanol adsorbed on permalloy at 90 K obtained at the start of a photolysis series. The points are the raw data; the dashed lines are the individual fitted components, and the solid line is the synthesized curve. The filled in region represents the C-O peak, which directly probes the chiral carbon. Also shown are models of (S)- and (R)-2-butanol. Image: ANL

( --The basic molecules that make up all living things have a predetermined chirality or "handedness,” similar to the way people are right- or left-handed. This chirality has a profound influence on the chemistry and molecular interactions of living organisms. The creation of chirality from the elementary building blocks of matter is one of the great mysteries of the origin of life. Scientists at the U.S. Department of Energy's Argonne National Laboratory have discovered a way to induce this handedness in pre-biological molecules.

"Understanding how the molecules necessary for life originated is one of the most basic scientific questions in biochemistry," said Argonne chemist Richard Rosenberg. "Chirality plays a fundamental role in biological processes, and researchers have been trying for years to discover the mechanisms that led to this property."

Rosenberg used X-rays from the Advanced Photon Source to bombard chiral molecules adsorbed on a magnetic substrate and X-ray photoelectron spectroscopy to track changes in their molecular bonds.

He found that changing the magnetization direction in relation to the high-intensity X-ray beam created an excess of one chirality over another. Changing the magnetization direction reverses the spin polarization of the secondary, or low-energy, electrons emitted from the substance.

Iron is a common element and is magnetic in many forms, and ionizing radiation and magnetic fields are prevalent throughout the universe.

Based on the Argonne results, it is conceivable that chirality could have been introduced by irradiation of molecules as they traveled through the universe while adsorbed on a magnetized substrate in a dust cloud, meteor, comet or on a primitive planet.

"Our study shows that spin-polarized secondary electrons interacting with chiral molecules could produce a significant excess of a given chirality in pre-biological molecules," Rosenberg said.

Argonne funded this research, which made use of a beamline at the Advanced Photon Source, an advanced X-ray light source built and funded by the Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science and used for advanced energy and materials science research.

A paper on Rosenberg's work appeared in a recent issue of Physical Review Letters.

Provided by Argonne National Laboratory

Explore further: Heat makes electrons spin in magnetic superconductors

Related Stories

Recommended for you

Heat makes electrons spin in magnetic superconductors

Apr 24, 2015

Physicists have shown how heat can be exploited for controlling magnetic properties of matter. The finding helps in the development of more efficient mass memories. The result was published yesterday in Physical Review Le ...

ICARUS neutrino experiment to move to Fermilab

Apr 23, 2015

A group of scientists led by Nobel laureate Carlo Rubbia will transport the world's largest liquid-argon neutrino detector across the Atlantic Ocean from CERN to its new home at the US Department of Energy's ...

National security on the move with high energy physics

Apr 23, 2015

Scientists are developing a portable technology that will safely and quickly detect nuclear material hidden within large objects such as shipping cargo containers or sealed waste drums. The researchers, led ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.