Biochemist Nermina Malanovic from the University of Graz has achieved a groundbreaking success in the fight against multiresistant pathogens. She has studied the properties of the synthetically produced peptides OP-145 and SAAP-148 and shown how these tiny protein fragments damage the outer shells of bacteria. Her paper even became the cover topic in the July issue of the journal “Antibiotics”.
“Multi-resistant pathogens in particular often have complex bacterial envelopes, which makes treatment so difficult,” explains Malanovic. “The University of Graz has strong expertise in studying these envelopes.” One focus is to clarify at which particular site on a bacterium's surface a certain drug works in the first place. “In the case of peptides, we have been investigating how these molecules make it into the cell interior.”
Destroys viruses, fungi, and cancer cells
“It was observed that it was frequently not even necessary for the peptides to penetrate the cell. They can change the cell membrane to such an extent that molecules from the environment of the bacterium can penetrate it. The cell is then not killed directly by the peptides, but cannot withstand the flood of foreign substances such as water or minerals.”
With these findings, it is now possible to combine different peptides in such a way that their effect against pathogens is enhanced. “Peptides kill bacteria, fungi, lipid-containing viruses like the coronavirus and even cancer cells.” The pathogens are destroyed so quickly that no resistance can form. Even the dreaded hospital pathogens can be destroyed in this way.
“Moreover, these peptides are anti-inflammatory and can be utilized in cases where pathogens compromise the immune system.” The molecular biologist cites viral diseases such as Covid-19 as an example. The course is typically massively worsened by secondary infections with bacteria or fungi. “Peptides target fundamental properties of cell membranes, thereby killing pathogens that can no longer induce inflammation.”
Why are they not already being used on a large scale: “The costs are currently very high. 100 milligrams come to around 2000 euros. Only special laboratories can produce these substances. Each peptide has to be treated specially,” Malanovic explains.
One of the goals of her work is therefore to understand the mechanism of such active molecules. Thanks to the new scientific findings, the design of novel peptides was possible, and the development process can be optimised. “This is really a first step towards victory against super-resistant bacteria.”
She has already invented two substances herself and applied for a patent together with the University of Graz.
Bactericidal Activity to Escherichia coli: Different Modes of Action of Two 24-Mer Peptides SAAP-148 and OP-145, Both Derived from Human Cathelicidine LL-37 https://www.mdpi.com/2079-6382/12/7/1163