Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Component of volcanic gas may have played a significant role in the origins of life on Earth

08.10.2004


Scientists at The Scripps Research Institute and the Salk Institute for Biological Studies are reporting a possible answer to a longstanding question in research on the origins of life on Earth--how did the first amino acids form the first peptides?


Peptides and proteins are strings of amino acid building blocks, and they are one of the most important classes of biological molecules found in living things today. Fifty years of chemical research on the origins of life has shown that amino acids could have formed spontaneously on the early Earth environment or could have been introduced onto the early Earth from meteorites.

"There are lots of ways to make amino acids," says Professor M. Reza Ghadiri, Ph.D., who is a member of The Skaggs Institute for Chemical Biology at Scripps Research. "But the question is, how do you couple them together?"

Ghadiri and Luke Leman, who is a member of the Kellogg School of Science and Technology at Scripps Research, worked out one possible solution with Leslie Orgel of the Salk Institute. In the latest issue of the journal Science, Leman, Ghadiri, and Orgel suggest that the missing link is a chemical component of volcanic gas known as carbonyl sulfide.



Carbonyl sulfide is present in volcanic gasses and deep sea vent emissions today, and since these geological phenomena were prominent features on the early Earth, it is reasonable to assume that the gas was present.

In their report, the scientists demonstrate that the gas can bring about a vigorous chemical reaction that forms peptides under mild aqueous conditions. Within a few minutes of introducing the gas to a reaction vessel containing amino acids, they observed high yields of di-, tri-, and tetra-peptides. They carried out the reaction in the presence of air, without air, and with and without other ingredients like metal ions, and they found peptides formed readily under all these conditions. "It’s really efficient, actually," says Ghadiri. "This addresses a very important question that we did not have a real good answer for."

Life--What We Know, and What We Don’t

The question of how life originated is one of the most interesting gaps in our knowledge--interesting perhaps because we know approximately when it occurred, but we do not know how it occurred.

The earliest fossils scientists have found are stromatolites--large clumps of cyanobacteria that grew in abundance in the ancient world over 3.5 billion years ago in what is now western Australia. These most likely evolved from some simpler life forms because, like all modern life, cyanobacteria are highly sophisticated living organisms--with cell walls, complex metabolism, and DNA genes. The question of the origins of life is: what came before the stromatolites?

Research on the origins of life has suggested the notion of an ancient RNA world--one in which RNA genes stored genetic information (something done by DNA today), carried out the chemistry necessary for life, and formed the essential physical structures of life (something done primarily by proteins today).

But how did that RNA world come about?

"Anybody who thinks they know the solution to this problem [of the origin of life] is deluded," says Orgel. "But," he adds, "anybody who thinks this is an insoluble problem is also deluded."

One possible approach to the problem of life’s origins is to ask the question scientifically rather than historically-- how can life emerge rather than how did life emerge. In order to address this, scientists try to determine experimentally what is chemically feasible and what could have occurred on the prebiotic earth.

One possibility, which was suggested in the 1920s by the Russian scientist A.I. Oparin, is that life emerged in its most primitive forms from minerals, metals, and the elements carbon, hydrogen, oxygen, and nitrogen, which were combined into amino acids, nucleotides, and the other the building blocks of life under the violent energy of lightning, solar radiation, comet impacts, and volcanic events that were present.

In 1953, this theory was given a boost when a paper was published in Science by Stanley L. Miller, who is Professor Emeritus at the University of California, San Diego. In the paper, Miller described an experiment he devised with Harold C. Urey--now called the Miller and Urey experiment--that gave experimental underpinnings to Oparin’s ideas.

In the experiment, Miller boiled H2O, CH4,H2, and NH3 gases in a glass apparatus containing a pair of tungsten electrodes. He subjected the chemicals to an electric discharge, intended to simulate conditions on the early Earth, and he collected and analyzed the molecules that formed--which included the amino acids alanine, glycine, and a few others. In the years since, several other investigators have expanded on the Miller–Urey experiment to demonstrate the formation and chemistry of many of the common biological amino acids, sugars, and nucleotides. Orgel, who is a long-time investigator in the field, has done pioneering research on the prebiotic chemistry of nucleotides.

This latest study is an advance because previous attempts to demonstrate the formation of peptides on early Earth depended on reaction schemes that were less plausible or were not as efficient. Next, the team plans to examine carbonyl sulfide’s reactive properties further and see if the gas can bring about other chemical reactions that are relevant to prebiotic chemistry.

Jason Bardi | EurekAlert!
Further information:
http://www.scripps.edu

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>