鱼皮是一种物理化学屏障,其特征是由分泌分子的细胞形成,这些分子负责抵御病原生物的第一防御。在这项研究中,鉴定并表征了来自Seriolalalandi和紫罗兰菌粘液的肽的生物活性。为此,从两个物种的青少年的表皮粘液样品中进行肽提取,使用色谱策略进行纯化。然后,通过质谱对肽提取物进行表征以获得氨基酸序列。使用生物信息学工具预测抗菌和抗氧化活性,选择使用Fmoc-Tbu策略通过同时合成化学产生的12种肽。结果显示合成肽呈现随机卷曲或延伸的二级结构。抗微生物活性的分析使其能够区分四种肽,以其合成代码5065、5069、5070和5076命名,具有抑制anguillarum弧菌生长的能力,并影响C.rogercresseyi的co足类阶段。另一方面,肽5066、5067、5070和5077具有最高的抗氧化能力。最后,肽5067,5069,5070和5076对诱导鱼白细胞的呼吸爆发最有效。组成与生物学功能之间的关联分析表明,抗菌活性取决于碱性和芳香族氨基酸的存在,而半胱氨酸残基的存在增加了肽的抗氧化活性。此外,据观察,那些具有最高抗菌能力的肽是那些也刺激白细胞呼吸爆发的肽。这是第一个证明智利海洋鱼类表皮粘液中存在功能肽的工作,当鱼面临机会病原体时,它们提供了不同的生物学特性。
The skin of fish is a physicochemical barrier that is characterized by being formed by cells that secrete molecules responsible for the first defense against pathogenic organisms. In this study, the biological activity of peptides from mucus of Seriola lalandi and Seriolella violacea were identified and characterized. To this purpose, peptide extraction was carried out from epidermal mucus samples of juveniles of both species, using chromatographic strategies for purification. Then, the peptide extracts were characterized to obtain the amino acid sequence by mass spectrometry. Using bioinformatics tools for predicting antimicrobial and antioxidant activity, 12 peptides were selected that were chemically produced by simultaneous synthesis using the Fmoc-Tbu strategy. The results revealed that the synthetic peptides presented a random coil or extended secondary structure. The analysis of antimicrobial activity allowed it to be discriminated that four peptides, named by their synthesis code 5065, 5069, 5070, and 5076, had the ability to inhibit the growth of Vibrio anguillarum and affected the copepodite stage of C. rogercresseyi. On the other hand, peptides 5066, 5067, 5070, and 5077 had the highest antioxidant capacity. Finally, peptides 5067, 5069, 5070, and 5076 were the most effective for inducing respiratory burst in fish leukocytes. The analysis of association between composition and biological function revealed that the antimicrobial activity depended on the presence of basic and aromatic amino acids, while the presence of cysteine residues increased the antioxidant activity of the peptides. Additionally, it was observed that those peptides that presented the highest antimicrobial capacity were those that also stimulated respiratory burst in leukocytes. This is the first work that demonstrates the presence of functional peptides in the epidermal mucus of Chilean marine fish, which provide different biological properties when the fish face opportunistic pathogens.