Two families of structurally related C-terminally alpha-amidated antimicrobial peptides have been identified in norepinephrine-stimulated skin secretions of the midwife toad Alytes obstetricans (Alytidae). The alyteserin-1 peptides (Gly-Leu-Lys-(Asp/Glu)-Ile-Phe-Lys-Ala-Gly-Leu-Gly-Ser-Leu-Val-Lys-(Gly/Asn)-Ile-Ala-Ala-His-Val-Ala-(Asn/Ser).NH(2)) show limited structural similarity to the ascaphins from the skins of frogs of the family Leiopelmatidae. Alyteserin-2a (Ile-Leu-Gly-Lys-Leu-Leu-Ser-Thr-Ala-Ala-Gly-Leu-Leu-Ser-Asn-Leu.NH(2)) and alyteserin-2b and -2c (Ile-Leu-Gly-Ala-Ile-Leu-Pro-Leu-Val-Ser-Gly-Leu-Leu-Ser-(Asn/Ser)-Lys-Leu x NH(2)) show limited sequence identity with bombinin H6, present in the skins of frogs of the family Bombinatoridae. The alyteserin-1 peptides show selective growth inhibitory activity against the Gram-negative bacteria Escherichia coli (MIC=25 microM) whereas alyteserin-2a is more potent against the Gram-positive bacteria Staphylococcus aureus (MIC=50 microM). The hemolytic activity against human erythrocytes of all peptides tested is relatively weak (LC(50)>100 microM). The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal's system of innate immunity.
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http://dx.doi.org/10.1016/j.peptides.2009.03.004 | DOI Listing |
Appl Environ Microbiol
January 2025
Animal Sciences Research Center, Division of Animal Sciences, University of Missouri, Columbia, Missouri, USA.
Antimicrobial peptides (AMPs) have emerged as potential alternatives to conventional antibiotics due to their novelty and multiple mechanisms of action. Because they are peptides, AMPs are amenable to bioengineering and suitable for cloning and expression at large production scales. However, the efficient delivery of AMPs is an unaddressed issue, particularly due to their large size, possible toxicities, and the development of adverse immune responses.
View Article and Find Full Text PDFFront Microbiol
December 2024
School of Biosciences and Technology, Vellore Institute of Technology SBST, Vellore, Tamil Nadu, India.
The emergence and re-emergence of multi-drug-resistant (MDR) infectious diseases have once again posed a significant global health challenge, largely attributed to the development of bacterial resistance to conventional anti-microbial treatments. To mitigate the risk of drug resistance globally, both antibiotics and immunotherapy are essential. Antimicrobial peptides (AMPs), also referred to as host defense peptides (HDPs), present a promising therapeutic alternative for treating drug-resistant infections due to their various mechanisms of action, which encompass antimicrobial and immunomodulatory effects.
View Article and Find Full Text PDFJ Immunol Res
December 2024
Department of Medical Microbiology, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye.
Antimicrobial peptides (AMPs) are crucial components of the innate immune system in all living organisms, playing a vital role in the body's defense against diseases and infections. The immune system's primary functions include preventing disease-causing agents from entering the body and eliminating them without causing harm. These peptides exhibit broad-spectrum activity against bacteria, viruses, fungi, parasites, and cancer cells.
View Article and Find Full Text PDFBiotechnol Rep (Amst)
March 2025
Laboratory of Peptide Biochemistry, Universidade Federal de São Paulo (UNIFESP), São José dos Campos, Brazil.
The biochemical analysis of animal venoms has been intensifying over the years, enabling the prediction of new molecules derived from toxins, harnessing the therapeutic potential of these molecules. From the venom of the fish , using methods for predicting antimicrobial and cell-penetrating peptides, two peptides from Natterins with promising characteristics were synthesized and subjected to and analysis. The peptides were subjected to stability tests and antimicrobial assays, cytotoxicity in murine fibroblast cells, antiviral assays against the Chikungunya virus, and the toxicity on was also evaluated.
View Article and Find Full Text PDFJ Biomol Struct Dyn
January 2025
Biochemistry and Bioinformatics Laboratory, Department of Applied Sciences, Indian Institute of Information Technology Allahabad (IIIT-A), Prayagraj, Uttar Pradesh, India.
Methicillin-resistant (MRSA), a major cause of fatalities due to Antimicrobial Resistance (AMR), can act as an opportunistic pathogen despite being part of the normal human flora. MRSA infections, such as skin infections, pneumonia, sepsis, and surgical site infections, have risen significantly, with bloodstream infection cases increasing from 21% in 2016 to 35% in 2020. This surge has prompted research into alternative treatments like nanomaterials, photodynamic therapy, antimicrobial peptides (AMPs), and essential oils (EOs).
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