Featured Research

from universities, journals, and other organizations

New Study By Scripps Scientists Sheds Light On Key Step For Origin Of Life

Date:
March 2, 2001
Source:
Scripps Research Institute
Summary:
Scientists at The Skaggs Institute for Chemical Biology, a part of The Scripps Research Institute (TSRI), have published a paper in the current issue of Nature that suggests a possible answer to how one of the early steps necessary for the origins of life arose. Principal Investigator M. Reza Ghadiri, Ph.D., Professor of Chemistry at TSRI, has created a biological polymer that can discriminate between two types of building blocks, taking those that are similar and building a copy of itself with them.

La Jolla, CA, February 15, 2001 -- Scientists at The Skaggs Institute for Chemical Biology, a part of The Scripps Research Institute (TSRI), have published a paper in the current issue of Nature that suggests a possible answer to how one of the early steps necessary for the origins of life arose.

Principal Investigator M. Reza Ghadiri, Ph.D., Professor of Chemistry at TSRI, has created a biological polymer that can discriminate between two types of building blocks, taking those that are similar and building a copy of itself with them.

The research article, "A Chiroselective Peptide Replicator," is authored by Alan Saghatelian, Yohei Yokobayashi, Kathy Soltani, and M. Reza Ghadiri.

Information transfer is one of the most fundamental requirements for life. Human DNA, for instance, lives in cell nuclei, where it makes RNA and protein products that carry out the work of the cell, (and in the big picture) our bodies. Part of this work is replicating and dividing the DNA so that the cell can split into two new daughter cells. Life is defined by these replication processes.

What is also known is that all the DNA, RNA, and protein molecules in our bodies are all homochiral. That is, the L-amino acids from which proteins are made and the D-riboses from which DNA and RNA are made are all chiral molecules. They come in two non-superimposable mirror image forms, like your right and left hand. Our bodies can only use the L-form of amino acids (left-handed) and the D-form of ribose molecules (right-handed).

Since only the correct forms of these building blocks of life can be used, a natural question arises. How did the very first biological molecules assemble out of a presumed mixture of right and left- handed building blocks?

To answer this, Ghadiri and his colleagues asked if a molecule that was correctly composed of all right or all left-handed components could replicate itself. They used peptides--short proteins of 32 amino acids--that naturally fold into a long helix and stick to another similar peptide, somewhat like the double barrels of a shotgun. They mixed right and left-handed versions of these peptides together with a mixture of their right and left-hand components.

For the "template" peptides to replicate, the correctly-handed components in the mixture would have to stick to the correct location on the peptides and then link up, forming exact copies of the template molecules, and this is exactly what they observed. The left-handed templates made more left-handed copies and the right-handed templates made right-handed copies from the mixed components.

Not only did the results show that the peptides favored the synthesis of correct duplicates, but the duplicates auto-catalyzed the reaction, speeding it up. They further discovered that if they added "mutant" peptide templates with a single incorrectly handed molecule, these would not make more mutant templates. They would instead correct the mistake and catalyze the formation of new molecules with the correct composition.

"That is astonishing," says Ghadiri. "Based on [our] understanding, polypeptides can self- replicate, form complex networks, error correct, form mutual systems, they have all sorts of emergent properties, and they can now do homochiral amplification."

The proof that a peptide system can self-replicate chiralselectively is strong evidence that such peptide chemistry could play an important role in the gestation of life on earth and elsewhere in the universe.

The research was funded (in part) by the NASA Astrobiology Institute, a national research consortium whose Central Office is located at NASA's Ames Research Center in Mt. View, CA The NAI, led by Director Baruch Blumberg, M.D, Ph.D. (Nobel laureate, '76), comprises 11 lead TEAMS and has international Affiliate and Associate Members.


Story Source:

The above story is based on materials provided by Scripps Research Institute. Note: Materials may be edited for content and length.


Cite This Page:

Scripps Research Institute. "New Study By Scripps Scientists Sheds Light On Key Step For Origin Of Life." ScienceDaily. ScienceDaily, 2 March 2001. <www.sciencedaily.com/releases/2001/02/010220072030.htm>.
Scripps Research Institute. (2001, March 2). New Study By Scripps Scientists Sheds Light On Key Step For Origin Of Life. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2001/02/010220072030.htm
Scripps Research Institute. "New Study By Scripps Scientists Sheds Light On Key Step For Origin Of Life." ScienceDaily. www.sciencedaily.com/releases/2001/02/010220072030.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins