NMR assisted studies on the solution structures and functions of antimicrobial peptides

Microbial resistance has now become a global public health concern, and the spread of multidrug-resistant bacteria also threatens human health. Antimicrobial peptides (AMPs) are a class of small peptides with antibacterial, anti-inflammatory, anti-infective, antioxidation, anti-tumor, antiviral functions and immune regulation activities. Due to the small sizes, their structures are easily studied by nuclear magnetic resonance (NMR) techniques. Compared to traditional antibiotics, AMPs have specific antibacterial mechanisms, and do not easily result in the production of drug-resistant strains. Thus, the development of new antimicrobial peptides and their wide use instead of chemical antibiotics are of great significance to human health. In this review, we first summarized the relationship between the structures and functions of antimicrobial peptides. Then, we focused on examples, cathelicidins, a group of cationic antimicrobial peptides with multiple biological activities. Especially, cathelicidin BF30 or BF34, composed of 30 or 34 amino acids, were from the venom glands of the Bungarus fasciatus snake and were considered to be the most active antibacterial peptides among different cathelicidin members. Their solution structures determined by NMR are a-helixes, which are useful in designing new and stable peptides with similar framework, including stapple peptides by inducing chemical modifications in the sidechains of some residues, as well as cyclic peptides by inducing disulfide bond between cysteines in the sequences. (c) 2022 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).