9ILX

Thanatin VF16QK in complex with LPS

9ILX の概要

• エントリーDOI: 10.2210/pdb9ilx/pdb
• 分子名称: VAL-PRO-ILE-ILE-TYR-CYS-ASN-ARG-ARG-THR-DLY-LYS-CYS-LYS-ARG-PHE (1 entity in total)
• 機能のキーワード: structure from cyana 2.1, antibiotic
• 由来する生物種: Podisus maculiventris
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 2030.53

構造登録者

Swaleeha, A.,Bhattacharyya, S. (登録日: 2024-07-01, 公開日: 2025-05-07)

主引用文献

Abdullah, S.J.,Guan, J.S.,Mu, Y.,Bhattacharjya, S.
Single Disulfide Bond in Host Defense Thanatin Analog Peptides: Antimicrobial Activity, Atomic-Resolution Structures and Target Interactions.
Int J Mol Sci, 26:-, 2024

PubMed Abstract: Host defense antimicrobial peptides (AMPs) are promising lead molecules with which to develop antibiotics against drug-resistant bacterial pathogens. Thanatin, an inducible antimicrobial peptide involved in the host defense of insects, is gaining considerable attention in the generation of novel classes of antibiotics. Thanatin or thanatin-based analog peptides are extremely potent in killing bacterial pathogens in the Enterobacteriaceae family, including drug-resistant strains of and . A single disulfide bond that covalently links two anti-parallel β-strands in thanatin could be pivotal to its selective antibacterial activity and mode of action. However, potential correlations of the disulfide covalent bond with structure, activity and target binding in thanatin peptides are currently unclear to. Here, we examined a 16-residue designed thanatin peptide, namely disulfide-bonded VF16QK, and its Cys to Ser substituted variant, VF16QK, to delineate their structure-activity relationships. Bacterial growth inhibitory activity was only detected for the disulfide-bonded VF16QK peptide. Mechanistically, both peptides vastly differ in their bacterial cell permeabilizations, atomic-resolution structures, interactions with the LPS-outer membrane and target periplasmic protein LptA binding. In particular, analysis of the 3-D structures of the two peptides revealed an altered folded conformation for the VF16QK peptide that was correlated with diminished LPS-outer membrane permeabilization and target interactions. Analysis of docked complexes of LPS-thanatin peptides indicated potential structural requirements and conformational adaptation for antimicrobial activity. Collectively, these observations contrast with those for the disulfide-bonded β-hairpin antimicrobial protegrin and tachyplesin peptides, where disulfide bonds are dispensable for activity. We surmise that the atomistic structures and associated molecular interactions presented in this work can be utilized to design novel thanatin-based antibiotics.

PubMed: 39795909
DOI: 10.3390/ijms26010051

実験手法

SOLUTION NMR