Magic polypeptides that can effectively deal with drug-resistant bacteria

The abuse of antibiotics around the world has received a lot of attention recently Because of overuse of antibiotics, more and more bacteria are resistant to antibiotics, resulting in the emergence of "super bacteria" At the same time, the development of new antibiotics has not kept pace with the evolution of bacteria According to the World Health Organization, by 2050, 10 million people may die of drug-resistant bacteria every year In order to update the arsenal for dealing with bacteria, some scientists have taken different measures Instead of developing and improving traditional antibiotics, they turned their attention to natural antimicrobial substances, some of which are protein fragments, called peptides Recently, researchers from the Massachusetts Institute of technology, Brasilia University and British Columbia University of Canada jointly designed an antibacterial peptide, which can eliminate many kinds of bacteria, including drug-resistant bacteria This achievement was published in scientific reports, a journal of Nature Publishing Group A variety of action mechanisms of antimicrobial peptides (photo source: pharmaceuticals) many organisms naturally produce antimicrobial peptides, which are an integral part of the body's autoimmune system They can not only kill invading bacteria, but also kill other microorganisms including fungi and viruses Their strength lies in their action on bacteria through many different mechanisms First of all, they can drill holes in the cell membrane of the invading bacteria After entering the bacteria, they can destroy multiple targets, including DNA, RNA and protein Secondly, they can activate the immune system of the organism itself and call on the white blood cells to completely eliminate the invading microorganisms This is also the biggest difference between these peptides and traditional antibiotics In addition, they can also inhibit systemic sepsis caused by overreaction of the immune system Naturally produced antimicrobial peptides are usually composed of 20 amino acids, including a positive region to help punch holes in the cell membrane, and a hydrophobic region to make it smoothly through the cell membrane into the bacteria With the development of modern computing technology, scientists can modify natural antibacterial peptides by replacing or adding new amino acids, and even design and manufacture new antibacterial peptides to make them more lethal In this study, scientists modified clavanin-a, an antibacterial peptide found in sea squirts, including adding five hydrophobic amino acids to make the whole peptide easier to enter the bacteria They called the new antimicrobial peptide clavanin mo It was found that clavanin Mo could eliminate the resistant strains of Escherichia coli and Staphylococcus aureus It can also destroy biofilms formed by bacteria on the surface of objects, such as Pseudomonas aeruginosa, which is often found in the lungs of patients with cystic fibrosis "Our goal is to find solutions for antibiotic resistance," said Dr Cesar de la fuente of the Massachusetts Institute of technology, one of the article's co authors Drug resistant bacteria are expected to surpass cancer and become the number one killer of human health Antimicrobial peptides provide an effective alternative Such a molecule can not only kill drug-resistant bacteria, but also strengthen immunity and prevent excessive immune response " The researchers plan to further improve the design of antibacterial peptides and finally put them into clinical use They believe that if combined with traditional antibiotics, bacteria can be more effectively eliminated and new drug resistance can be prevented.