ScienceDaily (Dec. 2, 2008) — 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 inception 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," Argonne chemist Richard Rosenberg said. "Chirality plays a fundamental role in biological processes and researchers have been trying to discover the mechanisms that led to this property for years."

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 the 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 form 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.

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

enlarge

Argonne chemist Richard Rosenberg examines source material for an experiment to induce chirality into pre-biological systems at the Advanced Photon Source. Rosenberg used X-ray photoelectron spectroscopy to measure the secondary electron induced photolysis reaction rate of a model chiral compound adsorbed on a magnetic substrate. He found that changing the magnetization direction in relation to the high-intensity X-ray beam created an excess of one chirality over another. (Credit: Image courtesy of DOE/Argonne National Laboratory)

Related Stories

Luminescence Shines New Light On Proteins (Nov. 14, 2008) — A chance discovery by a team of scientists using optical probes means that changes in cells in the human body could now be seen in a completely different ...  > read more

Scientists View Molecular Rendezvous (May 4, 2007) — A team of researchers has filmed pairs of molecules during recognition processes, which are vital to the functioning of organisms. The study shows that the shapes of the molecules change to ...  > read more

Improving Drug Design: Chemist Learn To Make Left Or Right Versions Of Synthetic Drug Molecules (June 9, 2008) — A chemist has apparently solved a long-standing frustration in creating certain synthetic molecules that make up drugs, which could lead to better drugs with fewer side effects. Like human hands, ...  > read more

Magnetic 'Handedness' Could Lead To Better Magnetic Storage Devices (May 30, 2007) — Better magnetic storage devices for computers and other electronics could result from new work by researchers in the United States and Germany. Their findings demonstrate that chirality -- a ...  > read more

Search ScienceDaily

Safety-Proofing Plastic