Abstract：
Pediocin and analogous bacteriocins, valued for thermal stability, serve as versatile antimicrobials in the food sector. Improving their resilience at high temperatures and deriving derivatives not only benefit food production but also offer broad-spectrum antimicrobial potential in pharmaceuticals, spanning treatments for peptic ulcers, women\'s health, and novel anticancer agents. The study aims to create mutant peptides capable of establishing a third disulfide bond or enhanced through cysteine substitutions. This involves introducing additional Cys residues into the inherent structure of pediocin PA-1 to facilitate disulfide bond formation. Five mutants (Mut 1-5) were systematically generated with double Cys substitutions and assessed for thermal stability through MD simulations across temperatures (298-394 K). The most robust mutants (Mut 1, Mut 4-5) underwent extended analysis via MD simulations, comparing their structural stability, secondary structure, and surface accessibility to the reference Pediocin PA-1 molecule. This comprehensive assessment aims to understand how Cys substitutions influence disulfide bonds and the overall thermal stability of the mutant peptides. In silico analysis indicated that Mut 1 and Mut 5, along with the reference structure, lose their helical structure and one natural disulfide bond at high temperatures, and may impacting antimicrobial activity. Conversely, Mut 4 retained its helical structure and exhibited thermal stability similar to Pediocin PA-1. Pending further experimental validation, this study implies Mut 4 may have high stability and exceptional resistance to high temperatures, potentially serving as an effective antimicrobial alternative.
摘要：
Pediocin和类似的细菌素，重视热稳定性，作为食品领域的多功能抗菌剂。提高其在高温下的弹性和衍生衍生物不仅有利于食品生产，而且在药物中提供广谱抗微生物潜力，跨越治疗消化性溃疡，妇女的健康，和新型抗癌剂。该研究旨在创建能够建立第三个二硫键或通过半胱氨酸取代增强的突变肽。这涉及将额外的Cys残基引入到儿茶素PA-1的固有结构中以促进二硫键形成。系统地产生具有双Cys取代的五个突变体(Mut1-5),并通过跨温度(298-394K)的MD模拟评估热稳定性。最强大的突变体（Mut1，Mut4-5）通过MD模拟进行了扩展分析，比较它们的结构稳定性，二级结构,和对参考PediocinPA-1分子的表面可达性。该综合评估旨在了解Cys取代如何影响二硫键和突变肽的整体热稳定性。硅片分析表明，Mut1和Mut5以及参考结构，在高温下失去螺旋结构和一个天然二硫键，并可能影响抗菌活性。相反，Mut4保留了其螺旋结构，并表现出与PediocinPA-1相似的热稳定性。有待进一步的实验验证，这项研究表明，Mut4可能具有很高的稳定性和优异的耐高温性，可能作为一种有效的抗菌替代品。
