The development of a cytosolic delivery strategy for biopharmaceuticals is one of the central issues in drug development. Knowledge of the mechanisms underlying these processes may also pave the way for the discovery of novel delivery systems. L17E is a an attenuated cationic amphiphilic lytic (ACAL) peptide developed by our research group that shows promise for cytosolic antibody delivery. In this study, given the high efficacy of L17E in cytosolic delivery, we investigated the mechanism of action of L17E in detail. L17E was found to achieve cytosolic delivery predominantly by transient disruption of the plasma membrane without the need for endocytosis. Importantly, the cell line selectivity studies of L17E revealed a strong correlation between the efficiency of L17E-mediated delivery and the expression level of KCNN4, the gene encoding the calcium-activated potassium channel KCa3.1. Genetic and pharmacological regulation of KCNN4 expression and KCa3.1 activity, respectively, correlate closely with the efficiency of L17E-mediated cytosolic delivery, suggesting the importance of membrane potential regulation by extracellular Ca2+ influx. Therefore, the activity of the L17E is relevant to the calcium-activated potassium channel.

中文翻译：

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KCNN4 作为减毒阳离子裂解肽 L17E 胞质递送的基因组决定簇。


生物制药的胞质递送策略的开发是药物开发的核心问题之一。了解这些过程背后的机制也可能为发现新的递送系统铺平道路。L17E 是由我们的研究小组开发的一种减毒阳离子两亲性裂解 （ACAL） 肽，在胞质抗体递送方面显示出前景。在这项研究中，鉴于 L17E 在胞质递送中的高效性，我们详细研究了 L17E 的作用机制。发现 L17E 主要通过瞬时破坏质膜实现胞质溶质递送，而无需内吞作用。重要的是，L17E 的细胞系选择性研究揭示了 L17E 介导的递送效率与 KCNN4 的表达水平之间有很强的相关性，KCNN4 是编码钙激活钾通道 KCa3.1 的基因。KCNN4 表达和 KCa3.1 活性的遗传和药理学调控分别与 L17E 介导的胞质递送的效率密切相关，表明细胞外 Ca2+ 内流对膜电位调节的重要性。因此，L17E 的活性与钙激活的钾通道有关。