Antimicrobial peptides

About: Antimicrobial peptides is a research topic. Over the lifetime, 10645 publications have been published within this topic receiving 507688 citations. The topic is also known as: host defense peptide & antimicrobial protein.

Penaeidins, a family of antimicrobial peptides from penaeid shrimp (Crustacea, Decapoda).

Abstract: The production of antimicrobial peptides represents a first-line host defense mechanism of innate immunity that is widespread in nature. Only recently such effectors were isolated in crustacean species, whereas numerous antimicrobial peptides have been characterized from other arthropods, both insects and chelicerates. This review presents findings on a family of antimicrobial peptides, named penaeidins, isolated from the shrimp Penaeus vannamei. Their structure and antimicrobial properties as well as their immune function will be discussed through analyses of penaeidin gene expression and peptide distribution upon microbial challenge.

The expanding world of extracellular traps: not only neutrophils but much more.

Abstract: The release of extracellular traps (ETs) is a recently described mechanism of innate immune response to infection. Although ETs have been intensely investigated in the context of neutrophil antimicrobial effector mechanisms, other immune cells such as mast cells, eosinophils, and macrophages can also release these structures. The different ETs have several features in common, regardless of the type of cells from which they originated, including a DNA backbone with embedded antimicrobial peptides, proteases, and histones. However, they also exhibit remarkable individual differences such as the type of sub-cellular compartments from where the DNA backbone originates (e.g., nucleus or mitochondria), the proportion of responding cells within the pool, and/or the molecular mechanism/s underlying the ETs formation. This review summarizes the knowledge accumulated in recent years regarding the complex and expanding world of ETs and their role in immune function with particular emphasis on the role of other immune cells rather than on neutrophils exclusively.

Antimicrobial activities of amphiphilic peptides covalently bonded to a water-insoluble resin.

Abstract: A series of polymer-bound antimicrobial peptides was prepared, and the peptides were tested for their antimicrobial activities. The immobilized peptides were prepared by a strategy that used solid-phase peptide synthesis that linked the carboxy-terminal amino acid with an ethylenediamine-modified polyamide resin (PepsynK). The acid-stable, permanent amide bond between the support and the nascent peptide renders the peptide resistant to cleavage from the support during the final acid-catalyzed deprotection step in the synthesis. Select immobilized peptides containing amino acid sequences that ranged from the naturally occurring magainin to simpler synthetic sequences with idealized secondary structures were excellent antimicrobial agents against several organisms. The immobilized peptides typically reduced the number of viable cells by > or = 5 log units. We show that the reduction in cell numbers cannot be explained by the action of a soluble component. We observed no leached or hydrolyzed peptide from the resin, nor did we observe any antimicrobial activity in soluble extracts from the immobilized peptide. The immobilized peptides were washed and reused for repeated microbial contact and killing. These results suggest that the surface actions by magainins and structurally related antimicrobial peptides are sufficient for their lethal activities.

Food applications of liposome-encapsulated antimicrobial peptides.

Abstract: Antimicrobial peptides have been extensively examined as potential biopreservatives in hurdle technology. However, stability issues like proteolytic degradation and the potential interaction of the antimicrobial peptide with food components might result in decreased antimicrobial activity. The entrapment of bacteriocins into liposomes might represent an alternative to overcome the problems related to the direct application of these antimicrobial peptides in food. Encapsulation of bacteriocins into liposomes is mainly reported to be achieved by the thin-film hydration method, and phosphatidylcholine is the most common phospholipid employed in liposome manufacture. This article reviews the main characteristics of liposomes, such as size, zeta-potential, and encapsulation efficiency. A detailed up-to-date summary of potential application of bacteriocin-loaded liposomes, with particular emphasis on nisin encapsulation, is presented.