Structure–activity relationships of antibacterial peptides

Abstract

Antimicrobial peptides play a crucial role in innate immunity, whose components are mainly peptide‐based molecules with antibacterial properties. Indeed, the exploration of the immune system over the past 40 years has revealed a number of natural peptides playing a pivotal role in the defence mechanisms of vertebrates and invertebrates, including amphibians, insects, and mammalians. This review provides a discussion regarding the antibacterial mechanisms of peptide‐based agents and their structure–activity relationships (SARs) with the aim of describing a topic that is not yet fully explored. Some growing evidence suggests that innate immunity should be strongly considered for the development of novel antibiotic peptide‐based libraries. Also, due to the constantly rising concern of antibiotic resistance, the development of new antibiotic drugs is becoming a priority of global importance. Hence, the study and the understanding of defence phenomena occurring in the immune system may inspire the development of novel antibiotic compound libraries and set the stage to overcome drug‐resistant pathogens. Here, we provide an overview of the importance of peptide‐based antibacterial sources, focusing on accurately selected molecular structures, their SARs including recently introduced modifications, their latest biotechnology applications, and their potential against multi‐drug resistant pathogens. Last, we provide cues to describe how antibacterial peptides show a better scope of action selectivity than several anti‐infective agents, which are characterized by non‐selective activities and non‐targeted actions toward pathogens.

Novel self-assembling cyclic peptides with reversible supramolecular nanostructures

“…Recently, cyclic peptides have emerged as the most promising novel peptide therapeutics. 77,90 As already reported in the literature, cyclization is a chemical strategy to improve peptide stability, half-life, and bioavailability.…”

“…Recently, cyclic peptides have emerged as the most promising novel peptide therapeutics. 77,90 As already reported in the literature, cyclization is a chemical strategy to improve peptide stability, half-life, and bioavailability. To date, only a small number of peptide sequences, comprising alternating d - and l -amino acids, have been designed to obtain cylindrical structures stabilized by non-covalent interactions.…”

“…S8 and Table S3, ESI †), emphasizing how cyclization stabilizes their structures, suggesting their usage in physiological environments where proteases resistance is required by the target application. [75][76][77]…”

A novel fluorescent traceable carbon quantum dots with selective antibacterial activity against Porphyromonas gingivalis

“…In recent years, nanomedicine has developed exponentially, and nanomaterials such as antibacterial peptides and inorganic nanoparticles have been developed as antibacterial drugs for the treatment of infectious diseases caused by bacteria. 11 Carbon quantum dots (CDs) exhibit excellent antibacterial properties due to their small size. As a new type of nanomaterial, its preparation is simple and easily modifiable, and it has many unique characteristics, such as excellent low toxicity, biocompatibility, high photostability, optical properties, good water solubility, and cell permeability.…”

Tuning the Anthranilamide Peptidomimetic Design to Selectively Target Planktonic Bacteria and Biofilm

“…In recent years, antimicrobial peptides (AMPs) have attracted significant attention as a new generation of antibiotics due to their low propensity to induce resistance [ 12 , 13 ]. AMPs are rich in both hydrophobic and cationic residues, and their positive charge allows them to attack bacterial membranes which are more negatively-charged relative to eukaryotic membranes [ 14 , 15 ]. However, AMPs are susceptible to proteolytic breakdown causing unexpected pharmacokinetics and toxicity, which has prevented their entry into the clinic [ 16 ].…”