Scientists have found a powerful antiseptic in the blood of "dragons"
Biologists have found an unusually powerful antiseptic in the blood of Komodo lizards that kills many dangerous bacteria, including some invulnerable "super-microbes" resistant to antibiotics, according to an article published in the journal npj Biofilms and Microbiomes (Chung et al., Komodo dragon-inspired synthetic peptide DRGN-1 promotes wound-healing of a mixed-biofilm infected wound).
"This substance is more than just an antiseptic or an antibiotic – the VK25 protein and its synthetic analogue DRGN-1 not only kill many different microbes, but also helps to heal wounds, stimulating the growth of skin cells and destroying bacterial films. All this indicates that this protein can be used as a base for a cream for the treatment of wounds," says Monique van Hoek from George Mason University in Fairfax (USA) and her colleagues.
Komodo lizards (Varanus komodoensis), or "dragons", as they are called by locals, are the largest species of lizards on Earth, the heirs of the giant three-meter mega-monitor lizards of Australia, with which the first aborigines of the southern continent fought. Monitor lizards are among the top ten most popular reptiles of the planet not only because of their size, but also the manner of hunting - they use a kind of "biological weapon" to get lunch.
The saliva and mouth of monitor lizards, as biologists discovered about ten years ago, contains a whole bunch of various deadly bacteria that cause sepsis and gangrene when ingested by humans or animals. Some scientists, however, dispute this possibility, believing that microbes get into the saliva of monitor lizards accidentally, along with the carrion they eat. In any case, these bacteria, despite their danger, do not interfere in any way with the life of the predator itself, which forced van Hook and her colleagues, as well as many other scientists, to look for substances in the blood of monitor lizards and in their saliva that protect them from microbial attacks.
To search for such secrets, van Hook's team developed special nanoparticles several years ago that allow "catching" various proteins from blood or cell samples, multiplying them and studying their structure. Using these particles, two years ago, van Hook and her colleagues found four dozen antiseptic proteins in the blood of alligators, and now they have tested their work on monitor lizards.
It turned out that the blood of monitor lizards contains a single, but very powerful antiseptic protein VK25. This substance, as shown by experiments on mice infected with different types of dangerous microbes, can destroy several types of pathogens at once, weakening their cell walls and destroying films of bacteria forming on the edges of the wound.
In particular, VK25 successfully destroyed colonies of Staphylococcus aureus, Pseudomonas aeruginosa, the killer bacterium Burkholderia thailandensis, which kills a person in 24 hours, as well as pathogens of tularemia and a number of other dangerous diseases.
In addition, this substance has another useful property – it stimulates the migration of skin cells and thereby accelerates the tightening of the wound, even in cases where there are no microbes and associated inflammatory processes.
Having discovered such an interesting substance, scientists tried to make it even more effective by introducing random mutations into the structure of the VK25 protein. The product of these efforts was the creation of the substance DRGN-1 – a more effective synthetic version of VK25, differing from the progenitor by only two amino acids.
In the near future, scientists plan to test whether DRGN-1 will suppress four other dangerous microbes infecting wounds, and will begin preclinical tests on rats and other animals.
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13.04.2017