The human body continues to surprise us. Just when we thought we had it all figured out, a discovery appears that overturns all certainties: the proteins we have always associated with blood clotting are actually factories of natural antibiotics.
A group of Spanish researchers has just demonstrated that some fragments of these proteins can eliminate the most resistant bacteria on the planet, including those that terrorize hospitals. The most incredible thing? These peptides already work perfectly, without the need for modification. It's like discovering that the key to your house also opens the bank safe.
How Heparin Proteins Become Bacteria Killers
Marc Torrent, researcher at the Department of Biochemistry and Molecular Biology of theAutonomous University of Barcelona, had an intuition that seemed crazy. "Certain proteins in our body that bind to heparin, a molecule that regulates processes such as blood clotting and inflammation, can also recognize similar structures present on the surface of dangerous bacteria," explains the study coordinator published Molecular Systems Biology.
Heparin It is a molecule we know well: anticoagulant, anti-inflammatory, essential for many vital processes. But no one had ever wondered what happens when the proteins that bind to it encounter similar bacterial structures. The response was surprising: they become ruthless killers.
The team used computational tools to explore more than one hundred glycosaminoglycan-binding proteins (HBPs), identifying and synthesizing fragments with antimicrobial potential. Among the selected candidates, Five laboratory-synthesized peptides showed potent activity against gram-negative bacteria including Escherichia coli, Pseudomonas aeruginosa e Acinetobacter baumannii, all responsible for serious hospital infections.
HBP-5 Peptide Conquers Sepsis Too
Of all the peptides tested, one in particular caught the attention: HBP-5. Not only can it effectively kill bacteria in the laboratory even at very low concentrations, but it also works as a sepsis killer in infected mice. The treatment was able to significantly reduce the bacterial load in several organs of the animals.
La sepsi, let us remember, is a major cause of death in hospitals: a systemic inflammatory response that can lead to organ failure. As highlighted in this article, antibiotic resistance is turning once-trivial infections into death sentences. Finding effective peptides against sepsis is a huge victory.
“These peptides stand out for their potency and specificity, with very low toxicity in human cells, indicating that they could be safe as a basis for future treatments,” he adds. Torrent.
Molecular Systems Biology (2025). DOI: 10.1038/s44320-025-00120-6
Natural antibiotics that do not create resistance
The most intriguing aspect of this discovery? These peptides could circumvent the problem of bacterial resistance. Unlike traditional antibiotics that aim to kill bacteria (thereby favoring the selection of resistant strains), many of these natural antimicrobial peptides work through different mechanisms.
The anti-virulence strategy, for example, it aims to disarm bacteria without killing them, reducing their ability to cause disease. It's like taking away the weapons of an invader without eliminating it: more difficult for it to develop countermeasures.
According to the data of the National Plan to Combat Antimicrobial Resistance (PNCAR) 2022-2025, Italy is among the European countries with the highest rates of antibiotic resistance. Every year, approximately 12.000 people die from resistant infections in our country. The discovery of these natural peptides opens a completely new path.
A family of natural antibiotics from our own bodies
This research reveals something extraordinary: We are literally full of potential natural antibioticsHeparin-binding proteins are distributed throughout the body, and many of them may contain fragments with yet-to-be-discovered antimicrobial activity.
“This opens the door to a new family of antibiotics derived from the body's own proteins, with the advantage that they can act specifically against resistant bacteria without affecting healthy cells,” he concludes. Torrent.
Think about it: while we spend billions searching for new molecules in the far corners of the Earth, the solution may have been there all along, hidden in the proteins that course through our veins. It’s a humbling but fascinating reminder that nature, even our own bodies, still has much to teach us.
The next steps involve optimizing culture conditions for producing these compounds and isolating sufficient quantities to elucidate their structures. There’s still a long way to go before these peptides become viable drugs, but the direction is clear: the war against superbugs could be won from within.
