Unlocking Life’s Origins: How Simple Molecules Formed Protocell Membranes on Early Earth

New Research on the Origins of Life

Scientists have studied how the first living cells may have formed on early Earth. This research, led by Professor Neal Devaraj at the University of California San Diego, explores how lipid membranes—the cell structures crucial for life—could have developed from simple molecules. The findings appear in the journal Nature Chemistry.

Importance of Lipid Membranes

Lipid membranes are essential for life. They create barriers to house a cell’s processes and reactions. Lipids consist of long chains of fatty acids. Early Earth likely had simple fatty molecules with fewer than 10 carbon bonds, but longer chains are necessary for building vesicles, which are structures that contain the machinery of life.

Key Discoveries: Lipid Formation Without Enzymes

Devaraj’s team examined how two basic molecules can create lipids. They used cysteine, an amino acid, and a short-chain thioester. By employing silica glass as a mineral catalyst, they facilitated a reaction between these molecules. On the silica surface, cysteine and thioesters produced stable lipid vesicles. This process required lower concentrations than would normally be necessary without a catalyst.

Devaraj stated, “We aim to understand how life can emerge from non-life. We offer one explanation for this transition.”

Reference

Christy J. Cho et al. (2024). “Protocells by spontaneous reaction of cysteine with short-chain thioesters.” Nature Chemistry. DOI: 10.1038/s41557-024-01666-y.

This research received support from the National Science Foundation and the National Institutes of Health.