Plectasin

Plectasin is a defensin-like peptide that was first isolated from the fungus Pseudoplectania nigrella. It is a potent antibacterial agent, particularly against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae (PRSP).

Structure

Plectasin is a small protein composed of 40 amino acids. It has a compact, globular structure, stabilized by three disulfide bonds. The structure of plectasin is similar to that of defensins, a class of antimicrobial peptides found in the immune systems of animals and plants.

Mechanism of Action

Plectasin exerts its antibacterial activity by binding to lipid II, a key component in the synthesis of bacterial cell walls. This binding inhibits cell wall biosynthesis, leading to cell death. Unlike many other antibiotics, plectasin does not induce resistance in bacteria, making it a promising candidate for the development of new antibacterial drugs.

Pharmacology

In preclinical studies, plectasin has shown potent activity against a range of Gram-positive bacteria, including MRSA and PRSP. It is also effective against bacteria that are resistant to other antibiotics. Plectasin is not toxic to human cells and has a low potential for inducing resistance.

Clinical Development

Plectasin is currently in the early stages of clinical development. It has been tested in animal models of infection, where it has shown efficacy against MRSA and PRSP. Clinical trials in humans are planned.

See Also

• Defensin
• Antibiotic resistance
• Methicillin-resistant Staphylococcus aureus
• Penicillin-resistant Streptococcus pneumoniae