Antimicrobial peptides

Abstract

Antimicrobial peptides (AMPs) are small molecular weight proteins with broad spectrum antimicrobial activity against bacteria, viruses, and fungi. These evolutionarily conserved peptides are usually positively charged and have both a hydrophobic and hydrophilic side that enables the molecule to be soluble in aqueous environments yet also enter lipid-rich membranes. Once in a target microbial membrane, the peptide kills target cells through diverse mechanisms. Cathelicidins and defensins are major groups of epidermal AMPs. Decreased levels of these peptides have been noted for patients with atopic dermatitis and Kostmann's syndrome, a congenital neutropenia. In addition to important antimicrobial properties, growing evidence indicates that AMPs alter the host immune response through receptor-dependent interactions. AMPs have been shown to be important in such diverse functions as angiogenesis, wound healing, and chemotaxis. As our knowledge of AMP biology expands, the precise role and relevance of these peptides will be better elucidated.

Olfactory ensheathing cells are attracted to, and can endocytose, bacteria

“…This potential role is supported by the fact that OECs express antimicrobial peptides that are an evolutionarily conserved component of the innate immune system. Antimicrobial peptides contain domains of hydrophobic and cationic amino acids that are spatially arranged into an amphipathic design to facilitate their insertion into the bacterial membrane, ultimately resulting in membrane destabilization and bacterial lysis [22][23][24]. Two antimicrobial peptides known to be expressed in OECs are Neuropeptide Y (NPY) and lysozyme [8,25,26].…”

Eurocin, a New Fungal Defensin

“…They kill their target rapidly (compared with conventional antibiotics the development of antimicrobial resistance is unlikely), and they have additional adjuvant effects on the immune system (21). In this paper we present the structure and mechanism of action of the new defensin eurocin isolated from the fungus Eurotium amstelodami.…”

Nanoparticles as Emerging Therapeutics for Coping Antimicrobial Drug Resistance

“…These peptides are wide-spread in all forms of life, from virus to parasites including bacterial cells [12]. The AMPs target broad spectrum of organisms used to interfere with microbial growth.…”