Related Experiment Video

Updated: Apr 16, 2026

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center
07:11

Constructing Cyclic Peptides Using an On-Tether Sulfonium Center

Published on: September 28, 2022

3.3K

Converting a Staphylococcus aureus toxin into effective cyclic pseudopeptide antibiotics

Olivia Solecki1, Amor Mosbah2, Michèle Baudy Floc'h2

  • 1U835 Inserm, Pharmaceutical Biochemistry, 2 Avenue du Professeur Léon Bernard, Rennes University, 35043 Rennes, France.

Chemistry & Biology
|March 3, 2015
PubMed

Insights

Staphylococcus aureus peptide toxin PepA1 shows antibacterial activity but causes red blood cell lysis. Modified PepA1 derivatives offer potent, safe antibacterial options by targeting bacterial envelopes.

Area of Science:

  • Microbiology
  • Biochemistry
  • Drug Discovery

Background:

  • Staphylococcus aureus produces peptide toxins for environmental response.
  • Previously identified PepA1 toxin induces lytic cell death in bacterial and host cells.
  • PepA1 exhibits potential antibacterial activity.

Purpose of the Study:

  • To evaluate the antibacterial activity of exogenously supplied PepA1.
  • To develop nonhemolytic derivatives of PepA1 for therapeutic use.
  • To elucidate the mechanism of action of PepA1 derivatives.

Main Methods:

  • Testing PepA1 activity against Gram-positive and Gram-negative bacteria.
  • Assessing hemolytic activity of PepA1 and its derivatives.
  • Synthesizing and characterizing cyclic peptide derivatives.
  • Investigating the mechanism of bacterial cell death induction.

Main Results:

  • Exogenous PepA1 displays broad-spectrum antibacterial activity but is highly hemolytic.
  • A cyclic heptapseudopeptide derivative shows reduced human cell toxicity and enhanced serum stability.
  • The cyclic derivative exhibits potent antibacterial activity.
  • Linear/helical PepA1 forms pores, while the cyclic form reorganizes bacterial envelopes with minimal erythrocyte effects.

Conclusions:

  • Bacterial toxins can serve as a basis for novel antibacterial drug development.
  • Modified peptide toxins offer a promising strategy to overcome limitations like host cell toxicity.
  • The cyclic PepA1 derivative represents a potential lead for new antibacterial agents.

More Related Videos

Development of a Backbone Cyclic Peptide Library as Potential Antiparasitic Therapeutics Using Microwave Irradiation08:48

Development of a Backbone Cyclic Peptide Library as Potential Antiparasitic Therapeutics Using Microwave Irradiation

Published on: January 26, 2016

12.6K
Construction of Cyclic Cell-Penetrating Peptides for Enhanced Penetration of Biological Barriers10:12

Construction of Cyclic Cell-Penetrating Peptides for Enhanced Penetration of Biological Barriers

Published on: September 19, 2022

3.0K

Related Concept Videos

Bacterial Toxins01:12

Bacterial Toxins

Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
97
Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
118
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within...
60
Inhibitors of Bacterial Protein Synthesis01:25

Inhibitors of Bacterial Protein Synthesis

Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
81
Production of Antibiotics01:27

Production of Antibiotics

Penicillin, one of the earliest and most widely used antibiotics, is produced industrially by the filamentous fungus Penicillium chrysogenum. Large stirred-tank bioreactors ranging from tens to hundreds of thousands of liters maintain tightly controlled temperature, pH, and dissolved oxygen conditions to support fungal metabolism and maximize antibiotic yield. Penicillin is a secondary metabolite, synthesized primarily during the stationary growth phase, which requires a carefully managed...
191
Lysogenic Cycle of Bacteriophages00:43

Lysogenic Cycle of Bacteriophages

In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
70.1K