Could antimicrobial peptides be an effective alternative to superbugs?

Antibiotics are becoming less effective due to bacterial resistance. Antimicrobial peptides have the potential to solve the resistance problem by physically destroying bacteria.

 

When it comes to medicines that are used to kill bacteria, antibiotics are probably the first thing that comes to mind. The first antimicrobial we developed was penicillin, which was derived from a blue mold, and antibiotics are still the most commonly used. In addition to antibiotics, there are other antibiotics found in our bodies or in nature, such as lysozyme and antimicrobial peptides. However, antibiotics are still the most popular because of their ability to kill germs and the fewer restrictions on their use. However, as bacteria have become resistant and patients have become infected with superbugs, there has been a growing interest in other antibiotics.
The antimicrobial peptides we’ll focus on in this article are, as the name suggests, peptides with the ability to kill bacteria. A peptide is a general term for a compound made up of amino acids, the building blocks of proteins, linked together by peptide bonds, usually no more than 100 amino acids. Antimicrobial peptides were first discovered in 1962 in the epidermal secretions of frogs, and have since been obtained and studied in many different organisms.
Antibiotics chemically neutralize bacteria by interfering with cell membrane components or protein synthesis. However, when bacteria mutate and change the way they synthesize cell membrane components, antibiotics no longer work. Bacteria are particularly prone to mutation, leading to the rise of antibiotic-resistant strains. Antimicrobial peptides, on the other hand, act specifically on the cell membrane of prokaryotes and physically disrupt it.
Antimicrobial peptides have both hydrophobic and hydrophilic parts, with the hydrophilic positively charged part strongly binding to the negatively charged cell membrane of the prokaryotic cell, and the hydrophobic part interacting with the hydrophobic part of the cell membrane to form holes in the cell membrane. This changes the permeability of the cell membrane and eventually destroys the cell. In eukaryotes, the alpha charge on the surface of the cell membrane is close to zero, which makes the interaction with antimicrobial peptides weak, and cholesterol reduces the fluidity of phospholipids, which inhibits the insertion of antimicrobial peptides into the cell membrane. Therefore, antimicrobial peptides are highly active in destroying prokaryotic cells while minimizing cell destruction in humans. This results in antimicrobial peptides killing bacteria faster and being more resistant to resistance.
While antimicrobial peptides have the advantage of killing bacteria quickly and reducing the likelihood of resistant bacteria, their ability to kill bacteria is less active than antibiotics. They are also limited in their ability to be degraded by proteases in the body. More research is needed to find antimicrobial peptides with stronger antimicrobial effects from different species to facilitate their use in humans. The problem of degradation by human enzymes requires research to chemically treat antimicrobial peptides from nature to prevent degradation or to find new antimicrobial peptides with resistance. In fact, HG1, an antibacterial peptide obtained from the silken horseshoe crab, has been developed as a drug to overcome these limitations and alleviate skin diseases such as atopy and acne. Research on antimicrobial peptides as new antibiotics, such as HG1, which is effective against skin diseases, is underway to study their anti-aging functions and the development of disease-resistant livestock.