• Investigating the antimicrobial effects and mechanism of action of antimicrobial peptides derived from the skin and brain of Bombina maxima
  • Mona Adel,1,* Tahereh Rezazadeh,2 Sina Parvaneh,3
    1. Department of Biology, East Tehran Branch, Islamic Azad University, Tehran, Iran
    2. Department of Biology, East Tehran Branch, Islamic Azad University, Tehran, Iran
    3. Islamic Azad University, Central Tehran branch


  • Introduction: Nowadays, due to the development of drug resistance in microorganisms, the need for a drug alternative is felt. Antimicrobial peptides (AMPs) are a class of active oligopeptides that are toxic to pathogens. AMPs are widely distributed in nature, and examples have been reported from microorganisms, plants, invertebrates, fish, amphibians, birds, and mammals. Amphibians are widely distributed in different continents except for polar regions. They are important sources for the isolation, purification, and identification of natural compounds including peptides with different functions. AMPs play an important role in repelling invading pathogens. Their other biological functions are endotoxin neutralization, chemotaxis, anti-inflammatory and wound healing. A large number of peptides have been isolated from Bombina maxima skin and brain secretions. Peptides belonging to the maximin family have strong antimicrobial activity and are very exciting candidates for drug development. In this research, we focus on Maximin 1,3 H5, which has received more attention than others.
  • Methods: An online search of published medical articles through PubMed, Scopus, Web of Science, and Google Scholar using the terms "Bombina maxima", "AMP", " Maximin H5", "maximin1", and "Maximin3". Numerous articles were reviewed and screened, and 19 articles were finally carefully investigated.
  • Results: AMPs are natural antibiotics known for their broad-spectrum resistance against bacteria, fungi, viruses, and parasites and for influencing host immune responses. In addition to antimicrobial activity, some antimicrobial peptides have biological activities such as anti-tumor and anti-HIV. Different from the bactericidal principle of traditional antibiotics with a single target, AMPs due to their broad‐spectrum antibacterial properties can destroy pathogens by damaging multiple targets, which can greatly reduce the emergence of drug‐resistant bacteria, and makes them one of the best alternatives for comprehensive antibiotics. The following table is an overview of some known maxims. maximins, a family of linear cationic peptides from skin secretions of B. maxima, differ from previously reported BLPs from different Bombina species in both structure and potency of biological activity. Due to their wide and distinct spectrum of biological activity (antimicrobial, antitumor, anti-HIV, spermicidal, potential new targets in mammals) on membranes, the central nervous system, and the gastrointestinal tract, they seem to have interesting potential for therapeutic application. Information about anionic peptides isolated from anuran amphibians, which could be part of the innate defense system, is scarce. maximin H5 is an example of this category, metal ions did not affect its antimicrobial power, this peptide creates a hemolytic effect by forming a diagonally oriented α-helix structure and inserting a tilted membrane. Maximin S1 has 14 amino acids and S2-S5 has 18 amino acids. Maximin 1-8, 10, 11 )Except for 6-8 which have 20 amino acids, the rest have 27 amino acids( and Maximin H1, 3-5, 7, 9, 10, 12, 15, 16 )Most of them have 20 amino acids( are other examples of antimicrobial peptides from Bombina maxima skin. Maximin 1 with the sequence: Gly-Ile-Gly-Thr-Lys-Ile-Leu-Gly-Gly-Val-Lys-Thr-Ala-Leu-Lys-Gly-Ala-Leu-Lys-Glu-Leu-Ala-Ser-Thr-Tyr-Ala-Asn 27 amino acids long, is a cationic and amphipathic antimicrobial peptide found in Bombina skin and brain secretions. Maximin1 is biologically interesting, as it possesses little hemolytic activity, and exhibits potent antimicrobial, anticancer, antiviral, anticancer, and spermicidal activity. This peptide is amphipathic and there is a clear separation between its polar and non-polar amino acids. Only a few amino acid differences distinguish maximin 3 from maximin 1 (position 4: tyrosine to glycine, position 8: glycine to serine, position 10: valine to leucine, position 18: leucine to alanine, position 26: alanine to leucine) that the change made in position 8 seems important. The first 22 amino acids form an alpha helix. Flexibility is observed around glycines 9 and 16 in the direction of hemolytic activity. This peptide has received much attention due to its anti-HIV properties.
  • Conclusion: Recombined and genetically engineered maxi mins are the best alternative or companion to traditional antibiotics due to their specific characteristics and are a promising way to prevent tumors and HIV viruses, etc. Researchers are investigating existing problems such as high synthesis cost, low efficacy, toxicity, etc. The present study investigates the maximins obtained from the skin and brain secretions of Bombina maxima.
  • Keywords: AMP Bombina maxima Maximin H5 maximin1 Maximin3