American Chemical Society's PressPac -- April 2, 2008

A simulated ribosome (white and purple subunits) processing an amino acid (green). Click here for more information.

ARTICLE #1

Meteorites delivered the “seeds” of Earth’s left-hand life
EMBARGOED FOR: Sunday, April 6, 8:30 a.m., Central Standard Time

Flash back three or four billion years — Earth is a hot, dry and lifeless place. All is still. Without warning, a meteor slams into the desert plains at over ten thousand miles per hour. With it, this violent collision may have planted the chemical seeds of life on Earth.

Scientists report that desert heat, a little water, and meteorite impacts may have been enough to cook up one of the first prerequisites for life: The dominance of “left-handed” amino acids, the building blocks of life on this planet. In an intriguing report, Ronald Breslow and colleagues describe how our amino acid signature came from outer space.

Chains of amino acids make up the protein found in people, plants, and all other forms of life on Earth. There are two orientations of amino acids, left and right, which mirror each other in the same way your hands do. This is known as “chirality.” In order for life to arise, proteins must contain only one chiral form of amino acids, left or right, Breslow notes. “If you mix up chirality, a protein’s properties change enormously. Life couldn’t operate with just random mixtures of stuff,” the researcher says.

With the exception of a few right-handed amino acid-based bacteria, left-handed “L-amino acids” dominate on earth. Amino acids delivered to Earth by meteorite bombardments left us with those left-handed protein units, Breslow and colleagues note. — AD

ARTICLE #1 EMBARGOED FOR: Sunday, April 6, 8:30 a.m., Central Standard Time

For full-text of press release with high-resolution images:
http://oasys.acs.org/output/process_last_run/acs/235nm/-acs-235nm-newsservice-webprogram-cgi.html

CONTACT:
Ronald Breslow, Ph.D.
Columbia University
New York, NY 10027
Phone: 212-854-2170
Email:

ARTICLE #2

Nuclear scientists eye future landfall on a second “island of stability”
EMBARGOED FOR: Sunday, April 6, 8:45 a.m., Central Standard Time