Quick summary
Cecropins are linear antimicrobial peptides from silk moth hemolymph, among the first insect immune peptides characterized. They show broad-spectrum antibacterial activity and serve as templates for synthetic hybrid antimicrobials.
Overview
Cecropins are a family of linear antimicrobial peptides originally isolated from the hemolymph of the silk moth Hyalophora cecropia. Consisting of 34–39 amino acids, cecropins were among the first insect innate immune peptides characterized. They display broad-spectrum activity against gram-positive and gram-negative bacteria and are templates for synthetic hybrid antimicrobials.
Mechanism of action
Cecropins adopt an N-terminal amphipathic alpha-helix connected via an Ala-Gly-Pro hinge to a hydrophobic C-terminal helix. The N-terminal helix binds electrostatically to bacterial membrane phospholipids, enabling insertion. At threshold concentrations, cecropins permeabilize bacterial outer and inner membranes through a combination of carpet-model disruption and pore formation. They also inhibit efflux pump activity and interact with intracellular nucleic acids. A conserved N-terminal tryptophan (position 1 or 2) is critical for full antimicrobial activity.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| antimicrobial research | topical | 1–50 mcg/mL | research use only | MIC range 1–50 mcg/mL depending on bacterial species and cecropin variant |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Cecropin A was isolated from H. cecropia in 1980 by Steiner et al. and is one of the founding members of the AMP field. Cecropin B has been extensively studied for its activity against MRSA, E. coli, P. aeruginosa, and biofilms. Cecropin A disrupts uropathogenic E. coli biofilms at sub-MIC concentrations. Hybrid peptides combining cecropin A and melittin (bee venom) N-terminal domains show potent antimicrobial activity with reduced mammalian cell toxicity. Antimalarial activity of Anopheles-derived cecropin-like peptides is under investigation. No cecropin is approved for clinical use.[1][2][3][4]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Cecropin for synergistic effects.
Legal status
Cecropin peptides are research reagents available from peptide suppliers. Not approved for human therapeutic use. Used primarily in academic antimicrobial research.
Sourcing & access
Research compound
Cecropin is classified as a research compound. Regulatory status varies by jurisdiction. Always verify current legal status and source from vendors providing third-party certificates of analysis (COA).
Frequently asked questions
Cecropins are a family of 34-39 amino acid linear antimicrobial peptides originally isolated from the hemolymph of the silk moth Hyalophora cecropia. They were among the first insect innate immune peptides characterized and display broad-spectrum activity against gram-positive and gram-negative bacteria.
Cecropins adopt an N-terminal amphipathic alpha-helix connected via a hinge to a hydrophobic C-terminal helix. The N-terminal helix binds electrostatically to bacterial membranes, enabling insertion and permeabilization through carpet-model disruption and pore formation. They also inhibit efflux pumps and interact with intracellular nucleic acids.
Cecropins have low hemolytic activity at physiological concentrations, making them relatively safe compared to many antimicrobial peptides. Cytotoxicity occurs only at supraphysiological doses. No cecropin is approved for clinical use; they remain research reagents.
Hybrid peptides combining the N-terminal domains of cecropin A and melittin (bee venom) show potent antimicrobial activity with reduced mammalian cell toxicity compared to either parent peptide. These hybrids represent a promising direction in AMP drug design.