Model of a protocell.
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Aug. 14, 2019
Research Highlight

Did Amino Acids Stabilize Prebiotic Membranes?

A possible solution to a long-standing question about early cells

Researchers supported in part by the Exobiology Program element of the NASA Astrobiology Program have recently featured in an article from The Atlantic. Their work focuses on the self assembly of fatty acid membranes on the early Earth, a process that could have led to the precursors of living cells.

Lead author Caitlin E. Cornell (left) is a graduate student with Professor Sarah L. Keller (right) in the Department of Chemistry at the University of Washington. The Keller laboratory is supported in part by the NASA Exobiology Program.
Lead author Caitlin E. Cornell (left) is a graduate student with Professor Sarah L. Keller (right) in the Department of Chemistry at the University of Washington. The Keller laboratory is supported in part by the NASA Exobiology Program.Image credit: University of Washington.

Living cells require a membrane that separates the contents of the cell (proteins, RNA, etc.) from the environment. It is thought that membranes could have spontaneously assembled from simple, polar fatty acids. However, fatty acid membranes would have been unstable in the environmental conditions that were likely present on the early Earth during the time of life’s origins.

The new research shows that prebiotic amino acids could have played a key role in stabilizing fatty-acid structures in the presence of salt and magnesium ions. Under the microscope, researchers observed that mixtures of amino acids and fatty acids were able to hold a spherical shape even when salt was present.

Click here to read the article from The Atlantic.

Sarah Keller of the University of Washington features in Issue #7 of the Astrobiology Graphic History series. Available at: https://astrobiology.nasa.gov/resources/graphic-histories/
Sarah Keller of the University of Washington features in Issue #7 of the Astrobiology Graphic History series. Available at: https://astrobiology.nasa.gov/resources/graphic-histories/

The study, “Prebiotic amino acids bind to and stabilize prebiotic fatty acid membranes,” was published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). The work was supported in part by NASA Astrobiology through the Exobiology Program.