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
New nanomedicine wipes out leukemia in animal study
In a promising advance for cancer treatment, Northwestern University scientists have re-engineered the molecular structure of a common chemotherapy drug, making it dramatically more soluble and effective and less toxic. In the new study, [...]
Mystery Solved: Scientists Find Cause for Unexplained, Deadly Diseases
A study reveals that a protein called RPA is essential for maintaining chromosome stability by stimulating telomerase. New findings from the University of Wisconsin-Madison suggest that problems with a key protein that helps preserve chromosome stability [...]
Nanotech Blocks Infection and Speed Up Chronic Wound Recovery
A new nanotech-based formulation using quercetin and omega-3 fatty acids shows promise in halting bacterial biofilms and boosting skin cell repair. Scientists have developed a nanotechnology-based treatment to fight bacterial biofilms in wound infections. The [...]
Researchers propose five key questions for effective adoption of AI in clinical practice
While Artificial Intelligence (AI) can be a powerful tool that physicians can use to help diagnose their patients and has great potential to improve accuracy, efficiency and patient safety, it has its drawbacks. It [...]
Advancements and clinical translation of intelligent nanodrugs for breast cancer treatment
A comprehensive review in "Biofunct. Mater." meticulously details the most recent advancements and clinical translation of intelligent nanodrugs for breast cancer treatment. This paper presents an exhaustive overview of subtype-specific nanostrategies, the clinical benefits [...]
It’s Not “All in Your Head”: Scientists Develop Revolutionary Blood Test for Chronic Fatigue Syndrome
A 96% accurate blood test for ME/CFS could transform diagnosis and pave the way for future long COVID detection. Researchers from the University of East Anglia and Oxford Biodynamics have created a highly accurate [...]
How Far Can the Body Go? Scientists Find the Ultimate Limit of Human Endurance
Even the most elite endurance athletes can’t outrun biology. A new study finds that humans hit a metabolic ceiling at about 2.5 times their resting energy burn. When ultra-runners take on races that last [...]
World’s Rivers “Overdosing” on Human Antibiotics, Study Finds
Researchers estimate that approximately 8,500 tons of antibiotics enter river systems each year after passing through the human body and wastewater treatment processes. Rivers spanning millions of kilometers across the globe are contaminated with [...]
Yale Scientists Solve a Century-Old Brain Wave Mystery
Yale scientists traced gamma brain waves to thalamus-cortex interactions. The discovery could reveal how brain rhythms shape perception and disease. For more than a century, scientists have observed rhythmic waves of synchronized neuronal activity [...]
Can introducing peanuts early prevent allergies? Real-world data confirms it helps
New evidence from a large U.S. primary care network shows that early peanut introduction, endorsed in 2015 and 2017 guidelines, was followed by a marked decline in clinician-diagnosed peanut and overall food allergies among [...]
Nanoparticle blueprints reveal path to smarter medicines
Lipid nanoparticles (LNPs) are the delivery vehicles of modern medicine, carrying cancer drugs, gene therapies and vaccines into cells. Until recently, many scientists assumed that all LNPs followed more or less the same blueprint, [...]
How nanomedicine and AI are teaming up to tackle neurodegenerative diseases
When I first realized the scale of the challenge posed by neurodegenerative diseases, such as Alzheimer's, Parkinson's disease and amyotrophic lateral sclerosis (ALS), I felt simultaneously humbled and motivated. These disorders are not caused [...]
Self-Organizing Light Could Transform Computing and Communications
USC engineers have demonstrated a new kind of optical device that lets light organize its own route using the principles of thermodynamics. Instead of relying on switches or digital control, the light finds its own [...]
Groundbreaking New Way of Measuring Blood Pressure Could Save Thousands of Lives
A new method that improves the accuracy of interpreting blood pressure measurements taken at the ankle could be vital for individuals who are unable to have their blood pressure measured on the arm. A newly developed [...]
Scientist tackles key roadblock for AI in drug discovery
The drug development pipeline is a costly and lengthy process. Identifying high-quality "hit" compounds—those with high potency, selectivity, and favorable metabolic properties—at the earliest stages is important for reducing cost and accelerating the path [...]
Nanoplastics with environmental coatings can sneak past the skin’s defenses
Plastic is ubiquitous in the modern world, and it's notorious for taking a long time to completely break down in the environment - if it ever does. But even without breaking down completely, plastic [...]
