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
The Unresolved Puzzle of Long COVID: 30% of Young People Still Suffer After Two Years
A UCL study found that 70% of young people with long Covid recovered within 24 months, but recovery was less likely among older teenagers, females, and those from deprived backgrounds. Researchers emphasized the need [...]
Needle-Free: New Nano-Vaccine Effective Against All COVID-19 Variants
A new nano-vaccine developed by TAU and the University of Lisbon offers a needle-free, room-temperature-storable solution against COVID-19, targeting all key variants effectively. Professor Ronit Satchi-Fainaro’s lab at Tel Aviv University’s Faculty of Medical and [...]
Photoacoustic PDA-ICG Nanoprobe for Detecting Senescent Cells in Cancer
A study in Scientific Reports evaluated a photoacoustic polydopamine-indocyanine green (PDA-ICG) nanoprobe for detecting senescent cells. Senescent cells play a role in tumor progression and therapeutic resistance, with potential adverse effects such as inflammation and tissue [...]
How Dysregulated Cell Signaling Causes Disease
Cell signaling is crucial for cells to communicate and function correctly. Disruptions in these pathways, caused by genetic mutations or environmental factors, can lead to uncontrolled cell growth, improper immune responses, or errors in [...]
Scientists Develop Super-Strong, Eco-Friendly Plastic That Bacteria Can Eat
Researchers at the Weizmann Institute have developed a biodegradable composite material that could play a significant role in addressing the global plastic waste crisis. Billions of tons of plastic waste clutter our planet. Most [...]
Building a “Google Maps” for Biology: Human Cell Atlas Revolutionizes Medicine
New research from the Human Cell Atlas offers insights into cell development, disease mechanisms, and genetic influences, enhancing our understanding of human biology and health. The Human Cell Atlas (HCA) consortium has made significant [...]
Bioeconomic Potential: Scientists Just Found 140 Reasons to Love Spider Venom
Researchers at the LOEWE Centre for Translational Biodiversity Genomics (TBG) have discovered a significant diversity of enzymes in spider venom, previously overshadowed by the focus on neurotoxins. These enzymes, found across 140 different families, [...]
Quantum Algorithms and the Future of Precision Medicine
Precision medicine is reshaping healthcare by tailoring treatments to individual patients based on their unique genetic, environmental, and lifestyle factors. At the forefront of this revolution, the integration of quantum computing and machine learning [...]
Scientists Have Discovered a Simple Supplement That Causes Prostate Cancer Cells To Self-Destruct
Menadione, a vitamin K precursor, shows promise in slowing prostate cancer in mice by disrupting cancer cell survival processes, with potential applications for human treatment and myotubular myopathy therapy. Prostate cancer is a quiet [...]
Scientists reveal structural link for initiation of protein synthesis in bacteria
Within a cell, DNA carries the genetic code for building proteins. To build proteins, the cell makes a copy of DNA, called mRNA. Then, another molecule called a ribosome reads the mRNA, translating it [...]
Vaping Isn’t Safe: Scientists Uncover Alarming Vascular Risks
Smoking and vaping impair vascular function, even without nicotine, with the most significant effects seen in nicotine-containing e-cigarettes. Researchers recommend avoiding both for better health. Researchers have discovered immediate impacts of cigarette and e-cigarette [...]
Twice-Yearly Lenacapavir for PrEP Reduces HIV Infections by 96%
Twice-yearly injections of the capsid inhibitor drug lenacapavir can prevent the vast majority of HIV infections, according to a Phase 3 clinical trial published Wednesday in the New England Journal of Medicine. HIV pre-exposure [...]
Did Social Distancing Begin 6,000 Years Ago? Neolithic Villagers May Have Invented It
Social distancing may have roots 6,000 years ago, as research shows Neolithic villages like Nebelivka used clustered layouts to control disease spread. The phrase “social distancing” became widely recognized in recent years as people [...]
Decoding Alzheimer’s: The Arctic Mutation’s Role in Unusual Brain Structures
Researchers have uncovered how certain genetic mutations lead to unique spherical amyloid plaques in inherited forms of Alzheimer’s, offering insights that could advance our understanding of the disease and improve therapeutic strategies. An international collaboration [...]
How Your “Lizard Brain” Fuels Overthinking and Social Anxiety
New research by Northwestern Medicine reveals how humans have evolved advanced brain regions to interpret others’ thoughts, connecting these areas with the amygdala, a part of the brain involved in emotional processing. Study sought [...]
How Did Life Begin? Researchers Discover Game-Changing Clue
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? [...]