Chemists have succeeded in achieving an important step in creating artificial life from scratch.
Chemists have succeeded in achieving an important step in creating artificial life from scratch. With the help of an innovative chemical reaction, they were able to produce cell membranes that organize independently - these membranes form the structural envelope that stores inside and supports the mechanisms required for life.
The findings of the research, led by chemistry professor Neal Devaraj from the University of California-San Diego, were published in the scientific journal Journal of the American Chemical Society.
"One of our long-term and very ambitious goals is to try and produce an artificial cell, a synthetic living unit from the ground up - in order to develop a living organism from non-living molecules that have never been associated with a living organism," notes the lead researcher. "Apparently, this mechanism did occur at least once during history - otherwise life would not have developed at all." By combining an essential component of ancient life together with non-biological starting materials the researchers hope to shine a spotlight on the origin of life.
"We don't really understand properly this very basic stage of our existence, how non-living matter evolved into living matter," explains the researcher. "Understanding this stage can tell us a lot - even what the chemical and biological principles are required for life."
Molecules that make up cell membranes have a chemical "head" that mixes easily with water and a chemical "tail" that repels them. In a water environment, these molecules form a double layer in which the heads stick out and the tails converge inward, creating a barrier that delimits the contents of the cell.
The researchers prepared similar molecules using an innovative reaction that causes the joining of two lipid chains. Nature uses complex enzymes that are themselves embedded in the membranes in order to complete this reaction, a fact that makes it very difficult to understand how the first membranes were formed.
"In our system we use a type of primitive catalyst - a very simple metal ion," the researcher points out. "The reaction itself is completely artificial - there is no biological equivalent to this chemical reaction. This is the mechanism by which completely innovative membranes can be created."
The researchers prepared the artificial membranes from an aqueous emulsion of oil and detergent. Alone - these components are stable. When metal ions are added, bubbles begin to form and stable tubes emerge from the oil droplets. After a few days, the oil drops disappear, due to the creation of membranes that organize independently.
Although other scientists recently announced the creation of a "biological cell", only its genome was truly artificial. All the rest was a bacterial cell. A completely artificial unit of life would require the unification of both a genome and a three-dimensional structure designed to house it.
The real value of this discovery lies in the simplicity of the reaction - from commercially available starting materials the scientists needed only one preparatory step to create each of the reacting fatty chains.
The news about the study
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The next time Deti argues with me on the subject I will know where to direct him
Not really serious. It is true that the cell envelope is very important to the cell, but defining success in building the envelope as an important stage in the development of life is less of a joke.
We are challenged to create life - enormous to the point of being impassable, and saying that the shell is an important step is like saying that building a fence around a desert area is a significant step in building a nuclear reactor in place.
http://www.ted.com/talks/lang/he/craig_venter_unveils_synthetic_life.html