Nowadays, drug-resistant microbes are becoming a serious clinical problem threatening people’s health and life. Antimicrobial peptides (AMPs) are believed to be potential alternatives of conventional antibiotics to combat the threat of drug-resistant microbes. However, the susceptibility of AMPs toward proteases is one of the major problems limiting their clinical use. In the present study, we reported the effect of Cu²⁺ on the bioactivity of AMP HMPI. We found that the addition of Cu²⁺ could improve the protease resistance of AMP HMPI without affecting its bioactivity. Notably, after the binding of Cu²⁺ with HMPI, the hemolytic activity of HMPI was greatly decreased. In addition, our results also demonstrated that the addition of Cu²⁺ increased the production of reactive oxygen species in the fungal cells, which may be a supplement for the antifungal activity of HMPI. In conclusion, the introduction of Cu²⁺ may provide an inorganic strategy to improve the stability and decrease the hemolytic activity of AMP HMPI, while maintaining its antifungal activity.

中文翻译：

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Cu 2+降低了抗菌肽HMPI的溶血活性，并增强了其对胰蛋白酶的抵抗力。

如今，耐药菌已成为威胁人们健康和生命的严重临床问题。抗菌肽（AMPs）被认为是常规抗生素对抗耐药菌威胁的潜在替代品。但是，AMPs对蛋白酶的敏感性是限制其临床应用的主要问题之一。在本研究中，我们报道了Cu ²⁺对AMP HMPI的生物活性的影响。我们发现添加Cu ²⁺可以提高AMP HMPI的蛋白酶抗性，而不会影响其生物活性。值得注意的是，Cu ²⁺与HMPI结合后，HMPI的溶血活性大大降低。此外，我们的结果还表明，添加Cu ²⁺增加了真菌细胞中活性氧的产生，这可能是HMPI的抗真菌活性的补充。总之，Cu ²⁺的引入可能为提高AMP HMPI的稳定性并降低其溶血活性，同时保持其抗真菌活性提供了一种无机策略。