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

(PhysOrg.com) --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: The risks of blowing your own trumpet too soon on research

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Hide and seek: Sterile neutrinos remain elusive

9 hours ago

The Daya Bay Collaboration, an international group of scientists studying the subtle transformations of subatomic particles called neutrinos, is publishing its first results on the search for a so-called ...

Novel approach to magnetic measurements atom-by-atom

14 hours ago

Having the possibility to measure magnetic properties of materials at atomic precision is one of the important goals of today's experimental physics. Such measurement technique would give engineers and physicists an ultimate ...

Scientists demonstrate Stokes drift principle

17 hours ago

In nature, waves – such as those in the ocean – begin as local oscillations in the water that spread out, ripple fashion, from their point of origin. But fans of Star Trek will recall a different sort of wave pattern: ...

User comments : 0