Crystal structure of mastoparan from Polistes jadwagae at 1.2Å resolution

X-ray Crystal Structures of Short Antimicrobial Peptides as Pseudomonas aeruginosa Lectin B Complexes

Herein, we report X-ray crystal structures of 11-13 residue antimicrobial peptides (AMPs) active against Pseudomonas aeruginosa as complexes of fucosylated d-enantiomeric sequences with the P. aeruginosa lectin LecB. These represent the first crystal structures of short AMPs. In 24 individual structures of eight different peptides, we found mostly α-helices assembled as two-helix or four-helix bundles with a hydrophobic core and cationic residues pointing outside. Two of the analogs formed an extended structure engaging in multiple contacts with the lectin. Molecular dynamics (MD) simulations showed that α-helices are stabilized by bundle formation and suggested that the N-terminal acyl group present in the linker to the fucosyl group can extend the helix by one additional H-bond and increase α-helix amphiphilicity. Investigating N-terminal acylation led to AMPs with equivalent and partly stronger antibacterial effects compared to the free peptide.

Single and multiple peptide γ-turns: literature survey and recent progress

Published data on peptide isolated and repetitive γ-turns are reviewed. Advancements in our laboratories on these 3D-structures are also presented.

Overview on the recent study of antimicrobial peptides: origins, functions, relative mechanisms and application

Antimicrobial peptides (AMPs), which are produced by several species including insects, other animals, micro-organisms and synthesis, are a critical component of the natural defense system. With the growing problem of pathogenic organisms resistant to conventional antibiotics, especially with the emergence of NDM-1, there is increased interest in the pharmacological application of AMPs. They can protect against a broad array of infectious agents, such as bacteria, fungi, parasite, virus and cancer cells. AMPs have a very good future in the application in pharmaceuticals industry and food additive. This review focuses on the AMPs from different origins in these recent years, and discusses their various functions and relative mechanisms of action. It will provide some detailed files for clinical research of pharmaceuticals industry and food additive in application.

Structural biology of allergens from stinging and biting insects

PURPOSE OF REVIEW

Modern techniques in genomic and protein research are applied to the study of stinging and biting insect allergens.

RECENT FINDINGS

Three-dimensional structures of additional insect venom and salivary allergens have been determined. An approach to determining B-cell epitopes has been used for hyaluronidase. A number of new venom and salivary allergens have been characterized. The structures and significance of several insect allergens have been updated. Investigations continue into distinguishing venom crossreactivity from multiple sensitization. Further studies are clarifying the significance of carbohydrate epitopes. Genomic and proteomic techniques are being used in the investigation of proteins and peptides in insect venom and saliva.

SUMMARY

The nature of venom crossreactivity and the B-cell and T-cell epitope structures of insect venom and salivary allergens are beginning to be elucidated.