Building cells from the outside in.

Scientists have come one step closer to creating artificial life by building a cell membrane from scratch:

“We don’t understand this really fundamental step in our existence, which is how non-living matter went to living matter,” [Neal Devaraj, assistant professor of chemistry at the University of California, San Diego] said. “So this is a really ripe area to try to understand what knowledge we lack about how that transition might have occurred. That could teach us a lot – even the basic chemical, biological principles that are necessary for life.”

Molecules that make up cell membranes have heads that mix easily with water and tails that repel it. In water, they form a double layer with heads out and tails in, a barrier that sequesters the contents of the cell.

Devaraj and [Itay Budin, a graduate student at Harvard University] created similar molecules with a novel reaction that joins two chains of lipids. Nature uses complex enzymes that are themselves embedded in membranes to accomplish this, making it hard to understand how the very first membranes came to be.

“In our system, we use a sort of primitive catalyst, a very simple metal ion,” Devaraj said. “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.”