Antimicrobial peptides of invertebrates. Part 1. structure, biosynthesis, and evolution

Abstract

Antimicrobial peptides and proteins (AMPs) are among the most important components of the immune system of multicellular organisms. The role of AMPs is of particular importance for invertebrates which constitute the vast majority of species diversity of the living world, because these animals lack acquired immunity. The AMPs of animal origin are ribosomally synthesized molecules that have, as a rule, a positive net charge and amphiphilic properties. They can act against bacteria, yeast and filamentous fungi, protozoa, and enveloped viruses. AMPs can also play a role of mediators of the immune system. Search and investiga tion for protective factors of the invertebrate host defense provide a better understanding of mechanisms of the innate immunity of humans and other mammals and give a key to a development of new medicines. The first part of this review focuses on special features of a structure, biosynthesis, regulation of gene expression, and molecular evolution of AMPs of invertebrates.

Innate Immune Memory in Invertebrate Metazoans: A Critical Appraisal

“…Despite a large structural diversity, AMPs have in common the ability to permeabilizing microbial membranes, leading to cell death. In general, e.g., in marine annelid, shrimp, oyster and horseshoe crab, AMPs are constitutively expressed, stored in circulating granular haemocytes, and secreted during an acute immune response ( 112 – 115 ), while in Drosophila anti-fungal peptides are induced upon phagocytosis ( 116 , 117 ). AMPs take part in determining the composition of the microbiota associated with the host ( 118 ), as they are robustly present in tissues/organs that are highly colonized by bacteria and in those that face external environments (terrestrial and aquatic).…”

Shedding Light on the Antimicrobial Peptide Arsenal of Terrestrial Isopods: Focus on Armadillidins, a New Crustacean AMP Family

“…AMPs, also known as host defense peptides (HDPs), are widespread in living organisms ranging from bacteria to humans, and are an evolutionarily conserved component of the innate immune system shared by all classes of life [4]. AMPs can inhibit or kill a broad spectrum of bacteria, fungi, yeast, protozoa and viruses at micromolar concentrations.…”

“…All AMPs share common features: (i) small size acids in length (ii) cationic and hydrophobic properties, and (iii) amphipathic structure [5]. Due to the extreme diversity in their primary structure, AMPs are commonly classified into three main classes according to their spatial structure and/or amino acid composition: (a) linear α-helical peptides, (b) linear peptides (enriched with amino acid residues such as Arg, Gly, Pro or Trp), and (c) cysteine-containing peptides (stabilized by intermolecular disulfide bonds) [4].…”

Transcriptome profiling and in silico detection of the antimicrobial peptides of red king crab Paralithodes camtschaticus

“…Along with direct antimicrobial action, AMPs are able to participate in the regulation of immune processes and tissue regeneration 11 . Fundamental studies of AMPs are closely related to their important applied value.…”

“…The development of resistance to AMPs is rather difficult, since it requires major changes in the structure and electrophysiological properties of the cell membrane 12 . AMPs increase the permeability of the cell membrane, thereby enhancing the effect of traditionally used antibiotics and can be used in combination with them 11 , 13 .…”