Biochemistry Genevan researchers decode the insertion mechanisms of bacteria
A Geneva research team has deciphered how certain pathogenic bacteria introduce harmful enzymes into host cells. They want to make use of this system to specifically transport drugs into cancer cells.
04.02.2025, 11:24
SDA
In addition, the knowledge gained could contribute to the development of new drugs that block the mechanism and fight bacterial infections. At the same time, it opens up possibilities for environmentally friendly biopesticides that specifically combat pests without affecting other organisms, as the University of Geneva announced on Tuesday.
Certain pathogenic bacteria use so-called Tc toxins to introduce their toxic enzymes into host cells. These toxins act as so-called molecular syringes: they attach themselves to a cell membrane, open a protein envelope and then inject the harmful substances in a targeted manner. In their study, published in the journal "Science Advances", the researchers from Geneva and Germany have now been able to show for the first time that this mechanism takes place via several intermediate states.
Up to 30 hours
Changes in pH or binding to receptors cause the protective protein envelope to open. Almost immediately afterwards, a protein channel is introduced into the target cell, through which the toxic enzyme enters the cell. According to the study, this process takes up to 30 hours in total.
The researchers used a combination of cryo-electron microscopy, single-molecule fluorescence spectroscopy and electron spin resonance spectroscopy to decipher the exact processes of the injection mechanism. These high-resolution methods made it possible to observe the structural changes of the Tc toxins in real time and to analyze their different intermediate states in detail.
