Rani Ruma, Poria Vikram, Jaglan Anu Bala, Kapoor Prexha, Bhutani Karan, Sharma Priya, Vaid R K, Bera B C, Virmani Nitin, Anand Taruna
National Centre for Veterinary Type Cultures (NCVTC), ICAR-National Research Centre on Equines, Hisar 125001, India.
National Centre for Veterinary Type Cultures (NCVTC), ICAR-National Research Centre on Equines, Hisar 125001, India.
Int J Biol Macromol. 2025 Aug;320(Pt 4):146105. doi: 10.1016/j.ijbiomac.2025.146105. Epub 2025 Jul 16.
Antimicrobial resistance in Salmonella poses significant threats, and engineered endolysins offer a promising alternative to traditional bacteriophage therapy. This study focuses on designing, developing, and evaluating a bacteriophage-derived engineered endolysin with a polycationic nonapeptide (PCNP) modification to enhance its activity. The sequence-encoded endolysin φSE218_Lys76 and its modified version φSE218_Lys76_L1_PCNP were cloned, expressed, purified, and assessed for their in-vitro antibacterial activity. Both endolysins were evaluated on live bacterial cells (with and without EDTA treatment) as well as on heat-killed bacterial cells and found antibacterial potential. The modified endolysin, φSE218_Lys76_L1_PCNP, exhibited significantly enhanced lytic activity compared to the parent endolysin, suggesting good electrostatic interactions with negatively charged bacterial surfaces. Additionally, molecular docking and dynamics simulations studies were used to check the binding affinity and structural stability of the modified endolysin on various peptidoglycan fragments. The results demonstrated a high binding affinity (-7.19 kcal/mol) and structural stability of modified endolysin with NAG-NAM tetramer, building blocks of peptidoglycan, in computational models, as compared to parent endolysin (-6.92 kcal/mol) which was found consistent with lytic activity observed in vitro. These findings highlight the potential of bacteriophage-derived endolysins as an alternative antimicrobial, offering a promising avenue for addressing the growing challenge of antibiotic-resistant pathogens.
沙门氏菌中的抗菌素耐药性构成了重大威胁，而工程化溶菌酶为传统噬菌体疗法提供了一种有前景的替代方案。本研究聚焦于设计、开发和评估一种经聚阳离子九肽（PCNP）修饰的噬菌体衍生工程化溶菌酶，以增强其活性。对序列编码的溶菌酶φSE218_Lys76及其修饰版本φSE218_Lys76_L1_PCNP进行了克隆、表达、纯化，并评估了它们的体外抗菌活性。两种溶菌酶均在活细菌细胞（有无EDTA处理）以及热灭活细菌细胞上进行了评估，并发现了抗菌潜力。与亲本溶菌酶相比，修饰后的溶菌酶φSE218_Lys76_L1_PCNP表现出显著增强的裂解活性，这表明其与带负电荷的细菌表面存在良好的静电相互作用。此外，还利用分子对接和动力学模拟研究来检查修饰后的溶菌酶与各种肽聚糖片段的结合亲和力和结构稳定性。结果表明，在计算模型中，修饰后的溶菌酶与肽聚糖的组成部分NAG-NAM四聚体具有较高的结合亲和力（-7.19千卡/摩尔）和结构稳定性，而亲本溶菌酶的结合亲和力为-6.92千卡/摩尔，这与体外观察到的裂解活性一致。这些发现突出了噬菌体衍生溶菌酶作为替代抗菌剂的潜力，为应对抗生素耐药病原体日益严峻的挑战提供了一条有前景的途径。
