In the fight against bacteria, researchers have scored a direct blow. They have made a breakthrough that would shorten the way of young and powerful antibiotics.
Source: University of Illinois
Rapid development of bacterial resistance to traditional antibiotics (such as penicillin or vancomycin) has become a major concern in public health. Since resistant bacteria can develop faster than the production of new antibiotics, understanding how these molecules function, can help drug factories to focus on producing and rapidly releasing powerful antibiotics.
As reported, scientists have deciphered the molecular mechanism of selective antimicrobial activity for a prototype class of synthetic constituents. Substances that mimic the antimicrobial peptides found in biological immune systems function as molecular “cutters” by blowing bacterial membranes. It’s like shooting them with a bullet hail of nanometric dimensions, so the perforated membranes are blown and bacteria die. The researchers also determined why some of the substances only act on bacteria, while others kill everything they arrive, including human cells. This method can be used for deciphering the most complicated mechanisms of antimicrobial molecules. “If we were to understand how these molecules work, then we could collect an arsenal of killer molecules with a slight variation and would not worry about antimicrobial resistance,” the researchers say.
In a collaboration between the University of Illinois and the University of Massachusetts, researchers initially synthesized a prototype class of antimicrobial ingredients, then used a narrow-angle X-ray synchrotron to examine the structures made of synthetic components and cell membranes.
Cell membrane (including some lipids that resemble traffic cones) regulates the passage of substances from the inside to the outside and vice versa. In the presence of the antimicrobial molecules of the researchers, lipid-shaped cones accumulate and collide through the cylindrical openings that pierce the membrane. After that, cell death occurs.
The effectiveness of an antimicrobial molecule depends on the concentration of the membrane lipid in the cone form and by the form of the antimicrobial molecule. For example, by easily changing the length of the synthetic molecule, researchers created antimicrobial molecules that would have no effect, either kill only bacteria, or kill everything they could achieve.
Understanding how these molecules kill bacteria and how to prevent their harmful action in human cells can develop a direct and rational way to produce new antibiotics.