MOSCOW, November 29. Tyumen State University scientists as part of a research team studied the mechanism of action of gliotoxin, an antibiotic produced by some soil microscopic fungi, on bacteria. According to researchers, the antimicrobial activity of gliotoxin is due to the fact that it affects the metal-containing enzymes of bacteria and “steals” zinc ions necessary for the enzymes to function. The results are presented in the scientific journal Biochimie.
Gliotoxin is a secondary metabolic product (metabolite) produced by some fungi of the genus Aspergillus. It is not directly involved in the processes of growth, reproduction and development of fungi, but helps them compete in nature with other microorganisms, said specialists from Tyumen State University (TSU).
The destructive effect of gliotoxin on microbes was discovered back in the 30s of the last century, but the mechanism of its antibacterial action still remained insufficiently detailed, experts noted. Previously, it was believed that the antimicrobial effect of gliotoxin develops due to the formation of reactive oxygen species inside cells.
TSU researchers as part of a scientific team found that gliotoxin damages the structures of cellular proteins, but, what is more unusual, removes zinc ions from cells, necessary for the normal functioning of metal-containing enzymes.
“Before this study, it was known that gliotoxin is capable of chelating zinc and copper ions from the metalloenzymes of eukaryotic microorganisms, we were the first to show that the same mechanism occurs in the case of prokaryotic organisms — bacteria,” said Alexey Vasilchenko, head of the laboratory of antimicrobial resistance of Tyumen State University .
According to him, gliotoxin showed great activity against gram-positive bacteria, including methicillin-resistant staphylococci, as well as yeast fungi of the genus Candida.
Scientists are now conducting new studies that will reveal the ecological role of gliotoxin in the life of soil fungi and potential risks for humans. The work was supported by the Russian Science Foundation.