New research offers a potential explanation for the formation of early Earth protocells.
Few questions have captivated humankind more than the mystery of life’s origins on Earth. How did the first living cells emerge? How did these early protocells develop the structural membranes essential for thriving and eventually assembling into complex organisms?
New research from the lab of University of California San Diego Professor of Chemistry and Biochemistry Neal Devaraj has uncovered a plausible explanation involving the reaction between two simple molecules. This work appears in Nature Chemistry.
The Role of Lipid Membranes in Life
Life on Earth requires lipid membranes – the structure of a cell that houses its interior mechanics and acts as a scaffold for many biological reactions. Lipids are made from long chains of fatty acids, but before the existence of complex life, how did these first cell membranes form from the simple molecules present on Earth billions of years ago?
Scientists believe that simple molecules of short fatty chains of fewer than 10 carbon-carbon bonds (complex fatty chains can have nearly twice that many bonds) were abundant on early Earth. However, molecules with longer chain lengths are necessary to form vesicles, the compartments that house a cell’s complicated machinery.
Time-lapse fluorescence microscopy video showing vesicle formation (images were taken every 2 minutes for 4 hours). Credit: Neal Devaraj lab / UC San Diego
While it may have been possible for some simple fatty molecules to form lipid compartments on their own, the molecules would be needed in very high concentrations that likely did not exist on a prebiotic Earth – a time when conditions on Earth may have been hospitable to life but none yet existed.
“On the surface, it may not seem novel because lipid production happens in the presence of enzymes all the time,” stated Devaraj, who is also the Murray Goodman Endowed Chair in Chemistry and Biochemistry. “But over four billion years ago, there were no enzymes. Yet somehow these first protocell structures were formed. How? That’s the question we were trying to answer.”
A Groundbreaking Discovery: Lipid Formation Without Enzymes
To uncover an explanation for these first lipid membranes, Devaraj’s team started with two simple molecules: an amino acid named cysteine and a short-chain choline thioester, similar to molecules involved in the biochemical formation and degradation of fatty acids.
The researchers used silica glass as a mineral catalyst because the negatively charged silica was attracted to the positively charged thioester. On the silica surface, the cysteine and thioesters spontaneously reacted to form lipids, generating protocell-like membrane vesicles stable enough to sustain biochemical reactions. This happened at lower concentrations than what would be needed in the absence of a catalyst.
“Part of the work we’re doing is trying to understand how life can emerge in the absence of life. How did that matter-to-life transition initially occur?” said Devaraj. “Here we have provided one possible explanation of what could have happened.”
Reference: “Protocells by spontaneous reaction of cysteine with short-chain thioesters” by Christy J. Cho, Taeyang An, Yei-Chen Lai, Alberto Vázquez-Salazar, Alessandro Fracassi, Roberto J. Brea, Irene A. Chen and Neal K. Devaraj, 30 October 2024, Nature Chemistry.
DOI: 10.1038/s41557-024-01666-y
This research was supported, in part, by National Science Foundation (EF-1935372) and the National Institutes of Health (R35-GM141939).

News
Instant coffee may damage your eyes, genetic study finds
A new genetic study shows that just one extra cup of instant coffee a day could significantly increase your risk of developing dry AMD, shedding fresh light on how our daily beverage choices may [...]
Nanoneedle patch offers painless alternative to traditional cancer biopsies
A patch containing tens of millions of microscopic nanoneedles could soon replace traditional biopsies, scientists have found. The patch offers a painless and less invasive alternative for millions of patients worldwide who undergo biopsies [...]
Small antibodies provide broad protection against SARS coronaviruses
Scientists have discovered a unique class of small antibodies that are strongly protective against a wide range of SARS coronaviruses, including SARS-CoV-1 and numerous early and recent SARS-CoV-2 variants. The unique antibodies target an [...]
Controlling This One Molecule Could Halt Alzheimer’s in Its Tracks
New research identifies the immune molecule STING as a driver of brain damage in Alzheimer’s. A new approach to Alzheimer’s disease has led to an exciting discovery that could help stop the devastating cognitive decline [...]
Cyborg tadpoles are helping us learn how brain development starts
How does our brain, which is capable of generating complex thoughts, actions and even self-reflection, grow out of essentially nothing? An experiment in tadpoles, in which an electronic implant was incorporated into a precursor [...]
Prime Editing: The Next Frontier in Genetic Medicine
By Dr. Chinta SidharthanReviewed by Benedette Cuffari, M.Sc. Discover how prime editing is redefining the future of medicine by offering highly precise, safe, and versatile DNA corrections, bringing hope for more effective treatments for genetic diseases [...]
Can scientists predict life longevity from a drop of blood?
Discover how a new epigenetic clock measures how fast you are really aging from just a drop of blood or saliva. A recent study published in the journal Nature Aging constructed an intrinsic capacity (IC) clock [...]
What is different about the NB.1.8.1 Covid variant?
For many of us, Covid-19 feels like a chapter we’ve closed – along with the days of PCR tests, mask mandates and daily case updates. But while life may feel back to normal, the [...]
Scientists discover single cell creatures can learn new behaviours
It was previously thought that learning behaviours only applied to animals with complex brain and nervous systems, but a new study has proven that this may also occur in individual cells. As a result, this new evidence may change how [...]
Virus which ’causes multiple organ failure’ found at popular Spanish holiday destination
British tourists planning trips to Spain have been warned after a deadly virus that can cause multiple organ failure has been detected in the country. The Foreign Office issued the alert on its dedicated website Travel [...]
Urgent health warning as dangerous new Covid virus from China triggers US outbreak
A dangerous new Covid variant from China is surging in California, health officials warn. The California Department of Public Health warned this week the highly contagious NB.1.8.1 strain has been detected in the state, making it the [...]
How the evolution of a single gene allowed the plague to adapt, prolonging the pandemics
Scientists have documented the way a single gene in the bacterium that causes bubonic plague, Yersinia pestis, allowed it to survive hundreds of years by adjusting its virulence and the length of time it [...]
Inhalable Nanovaccines: The Future of Needle-Free Immunization
The COVID-19 pandemic highlighted the need for adaptable and scalable vaccine technologies. While mRNA vaccines have improved disease prevention, most are delivered by intramuscular injection, which may not effectively prevent infections that begin at [...]
‘Stealthy’ lipid nanoparticles give mRNA vaccines a makeover
A new material developed at Cornell University could significantly improve the delivery and effectiveness of mRNA vaccines by replacing a commonly used ingredient that may trigger unwanted immune responses in some people. Thanks to [...]
You could be inhaling nearly 70,000 plastic particles annually, what it means for your health
Invisible plastics in the air are infiltrating our bodies and cities. Scientists reveal the urgent health dangers and outline bold solutions for a cleaner, safer future. In a recent review article published in the [...]
Experts explain how H5 avian influenza adapts to infect more animals
A new global review reveals how rapidly evolving H5 bird flu viruses are reaching new species, including dairy cattle, and stresses the urgent need for coordinated action to prevent the next pandemic. Since its [...]