Ferreira Carolina Silva, Costa Lívia Mara Fontes, Nunes Lúcio Otávio, de Souza Kelton Rodrigues, Araújo Giovanna Paula, Salnikov Evgeniy S, Kato Kelly Cristina, Martins Helen Rodrigues, de Castro Pimenta Adriano Monteiro, Resende Jarbas Magalhães, Bechinger Burkhard, Verly Rodrigo Moreira
Department of Chemistry, Federal University of the Jequitinhonha and Mucuri Valleys, Diamantina 39100-000, MG, Brazil.
Institute of Science and Technology, Federal University of the Jequitinhonha and Mucuri Valleys, Diamantina 39100-000, MG, Brazil.
Pharmaceuticals (Basel). 2025 Jun 24;18(7):952. doi: 10.3390/ph18070952.
The increasing prevalence of multidrug-resistant bacteria presents a major global health challenge, prompting a search for innovative antimicrobial strategies. This study aimed to develop and evaluate a novel nanobiostructure combining alumina nanoparticles (NPs) with the antimicrobial peptide lunatin-1 (Lun-1), forming peptide-functionalized nanofilaments. The main objective was to investigate how the site of peptide functionalization (C-terminal vs. N-terminal) affects membrane interactions and antibacterial activity. : NP-peptide conjugates were synthesized via covalent bonding between lun-1 and alumina NP and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), zeta potential analysis, dynamic light scattering (DLS), Fourier-transform infrared (FTIR), and solid-state C NMR. Antibacterial activities were assessed against different Gram-positive and Gram-negative strains. Biophysical analyses, including circular dichroism (CD), isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), and solid-state H NMR, were employed to evaluate peptide-membrane interactions in the presence of membrane-mimetic vesicles composed of POPC:POPG (3:1) and DMPC:DMPG (3:1). : Characterization confirmed the successful formation of NP-peptide nanofilaments. Functionalization at the N-terminal significantly influenced both antibacterial activity and peptide conformation compared to C-terminal attachment. Biophysical data demonstrated stronger membrane interaction and greater membrane disruption when lun-1 was conjugated at the N-terminal. : The site of peptide conjugation plays a crucial role in modulating the biological and biophysical properties of NP-lunatin-1 conjugates. C-terminal attachment of lunatin-1 retains both membrane interaction and antibacterial efficacy, making it a promising strategy for the design of peptide-based nanotherapeutics targeting resistant pathogens.
多重耐药菌的日益流行对全球健康构成了重大挑战，促使人们寻找创新的抗菌策略。本研究旨在开发和评估一种新型纳米生物结构，将氧化铝纳米颗粒（NPs）与抗菌肽lunatin-1（Lun-1）结合，形成肽功能化纳米丝。主要目的是研究肽功能化位点（C端与N端）如何影响膜相互作用和抗菌活性。通过lun-1与氧化铝NP之间的共价键合合成NP-肽缀合物，并使用透射电子显微镜（TEM）、X射线衍射（XRD）、zeta电位分析、动态光散射（DLS）、傅里叶变换红外（FTIR）和固态C NMR进行表征。评估了对不同革兰氏阳性和革兰氏阴性菌株的抗菌活性。采用包括圆二色性（CD）、等温滴定量热法（ITC）、差示扫描量热法（DSC）和固态H NMR在内的生物物理分析方法，评估在由POPC:POPG（3:1）和DMPC:DMPG（3:1）组成的膜模拟囊泡存在下的肽-膜相互作用。表征证实成功形成了NP-肽纳米丝。与C端连接相比，N端功能化对抗菌活性和肽构象均有显著影响。生物物理数据表明，当lun-1在N端缀合时，膜相互作用更强，膜破坏更大。肽缀合位点在调节NP-lunatin-1缀合物的生物学和生物物理性质方面起着关键作用。lunatin-1的C端连接保留了膜相互作用和抗菌功效，使其成为设计针对耐药病原体的基于肽的纳米治疗药物的有前景策略。
