"The materials do not separate completely with one type of macromolecule in one section and the other completely apart," says Keating. "But the two aqueous phases are different enough that additional molecules, such as proteins or nucleic acids, prefer one over the other and will become concentrated there."
In bulk materials, researchers have been able to cause aqueous phase separation of up to 15 different compounds. Similar, multiple separations might even take place in a cell's cytoplasm. Biologists know that enzymes and other proteins tend to clump together or collocate in certain parts of the cell at certain times.
This collocalization would make the chemical reactions in metabolic pathways occur more rapidly because the chemicals necessary for the next step would be located nearby.
The application of heat, or a change in osmotic pressure can cause the separated materials to mix. However, upon cooling or reversion to the initial pressure, the materials again separate.
"It should be possible to collocalize materials in an artificial cell and then have the process be reversible," said Keating. "We could then bring together molecules we want at a certain time and separate them to control their activity."
Keating believes that some of the chemical reactions in cells may be controlled by collocation. If she can reproduce this type of collocation in her artificial cells, the systems can be more easily studied.
"The answer to whether or not collocalization can play this role is probably yes," said Keating. "However, proving it is not easy. With a simple reversible model system, we could test this idea and learn how large an effect is possible."
These primitive cells also model
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