Background: While several biologics have been reported from different parts of Clitoria ternatea, a herbaceous climber of the family Fabaceae, specific production of cationic peptides other than cyclotides (<3.7 kDa) has barely been investigated, or their bioactive potential been looked into.

Objective: The study aims to uncover potential bioactivities and characteristics of novel cationic peptides from C. ternatea seeds.

Methods: C. ternatea seed cationic peptide purified by simple and cost-effective procedures was analyzed by electrophoresis and mass spectrometry. Antimicrobial efficacy was evaluated against bacterial and fungal pathogens. Antioxidant potential was quantified by in vitro antioxidant assays. Physicochemical characterization and Tandem mass spectrometry were performed.

Results: An 8.5 kDa cationic peptide purified from C. ternatea seeds was active against Candida albicans, Staphylococcus aureus, Aeromonas hydrophila and Escherichia coli at a minimum inhibitory concentration in the range of 8-32 μg/ml. This activity was totally uncompromised at pH 5-8 or after 1 h of heat treatment at 70-80ºC, but was sensitive to protease treatment. Concentration-dependent free-radical scavenging activity and ferric-reducing capacity demonstrated the antioxidant potential of the peptide. Tandem MS analysis of trypsin-digested peptide based on shotgun proteomics detected matching peptide sequences with one or two cysteine residues but had low sequence coverage (≤17%) to known sequences in the C. ternatea protein database. Taken together, the distinct characteristics of this novel 8.5 kDa peptide clearly distinguish it from known cyclotides of C. ternatea.

Conclusions: Insights have been obtained into the functional characteristics of what appears to be a novel cationic peptide from C. ternatea seeds, exhibiting significant antimicrobial and antioxidant activities.

背景：虽然已经报道了来自豆科植物 Clitoria ternatea 的不同部分的几种生物制剂，但几乎没有研究过除环肽 (<3.7 kDa) 以外的阳离子肽的特定生产，或者对其生物活性潜力进行了研究。

目的：本研究旨在揭示 C. ternatea 种子中新型阳离子肽的潜在生物活性和特性。

方法：通过电泳和质谱分析通过简单且经济有效的程序纯化的三叶菜种子阳离子肽。对细菌和真菌病原体的抗菌功效进行了评估。通过体外抗氧化测定来量化抗氧化潜力。进行了物理化学表征和串联质谱分析。

结果：从 C. ternatea 种子中纯化的 8.5 kDa 阳离子肽对白色念珠菌、金黄色葡萄球菌、嗜水气单胞菌和大肠杆菌具有活性，最小抑制浓度为 8-32 μg/ml。这种活性在 pH 5-8 或在 70-80ºC 热处理 1 小时后完全不受影响，但对蛋白酶处理敏感。浓度依赖性自由基清除活性和铁还原能力证明了肽的抗氧化潜力。基于鸟枪法蛋白质组学的胰蛋白酶消化肽的串联 MS 分析检测到具有一个或两个半胱氨酸残基的匹配肽序列，但对 C. ternatea 蛋白质数据库中的已知序列的序列覆盖率较低 (≤17%)。综合来看，这部小说的鲜明特点 8。

结论：已经获得了对似乎是来自 C. ternatea 种子的一种新型阳离子肽的功能特征的见解，它表现出显着的抗菌和抗氧化活性。