In previous work, the team created a membrane that was entirely uniform, but in their most recent paper, they describe an asymmetric membrane containing a mixture of lipid molecules. Some of these lipid molecules contained tiny pieces of PEG, which interacted with the PEG in the cytoplasm, thus generating polarity in the model cell. "Our work demonstrated the interrelationship of the cytoplasm and the cell membrane," said Keating.
The team's next step is to create a cascade in polarity. "By creating a model cytoplasm with different compositions, we demonstrated that we can control the behavior of cell membranes," said Keating. "Now we want to find out what will happen if, for example, we add an enzyme whose activity depends on the compositions of the cytoplasm and cell membrane."
Although Keating and her colleagues plan to continue adding components to their model cell, they don't expect to make a real cell. "We aren't trying to generate life here. Rather, we want to understand the physical principles that govern biological systems," said Keating. "For me the big picture is trying to understand how the staggering complexity observed in biological systems might have arisen from seemingly simple chemical and physical principles."
|Contact: Barbara K. Kennedy|