Chemists have made a big step towards the creation of a completely artificial life form.
A team from Harvard University and the University of California, San Diego has created self-assembling cell membranes, the structural envelopes that contain and support the reactions required for life.
Nearly two years ago, biologist Craig Venter announced that his team had created an artificial cell. However, only the DNA was truly synthetic, and was housed in a natural biological cell.
“One of our long term, very ambitious goals is to try to make an artificial cell, a synthetic living unit from the bottom up – to make a living organism from non-living molecules that have never been through or touched a living organism,” says UCL assistantr professor Neal Devaraj.
“Presumably this occurred at some point in the past. Otherwise life wouldn’t exist.”
The molecules that make up cell membranes have heads that mix easily with water and tails that repel it. In water, therefore, they form a double layer with heads out and tails in, creating a barrier.
Devaraj and Harvard graduate student Itay Budin created similar molecules with a novel reaction that joins two chains of lipids – soemthing not seen in nature.
“In our system, we use a sort of primitive catalyst, a very simple metal ion,” Devaraj says. “The reaction itself is completely artificial. There’s no biological equivalent of this chemical reaction. This is how you could have a de novo formation of membranes.”
Thehe synthetic membranes were created from a watery emulsion of oil and detergent, stable as it stands. But when copper ions are added, sturdy vesicles and tubules begin to bud off the oil droplets – and, after 24 hours, the oil droplets are gone, consumed by the self-assembling membranes.
The biggest surprise of this discovery may be its simplicity.
“It’s trivial and can be done in a day,” says Devaraj. “New people who join the lab can make membranes from day one.”