Inhibitor K562 (IK) protein was first isolated from the culture medium of K562, a leukemia cell line, and is an inhibitory regulator of interferon-γ-induced major histocompatibility complex class II expression. Recently, exogenous truncated IK (tIK) protein showed potential as a therapeutic agent for inflammation-related diseases. In this study, we designed a novel putative anti-inflammatory peptide derived from tIK protein based on homology modeling of the human interleukin (IL)-10 (hIL-10) structure, and investigated whether the peptide exerted inhibitory effects against pro-inflammatory cytokines such as IL-17 and tumor necrosis factor-α (TNF-α). The peptide contains key residues involved in binding hIL-10 to the IL-10 receptor, and exerted strong inhibitory effects on IL-17 (43.8%) and TNF-α (50.7%). In addition, we used circular dichroism spectroscopy to confirm that the peptide is usually present in a random coil configuration in aqueous solution. In terms of toxicity, the peptide was found to be biologically safe. The mechanisms by which the short peptide derived from human tIK protein exerts inhibitory effects against IL-17 and TNF-α should be explored further. We also evaluated the feasibility of using this novel peptide in skincare products.

中文翻译：

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截短的 IK 蛋白衍生肽对两种促炎细胞因子 IL-17 和 TNF-α 的抑制作用。

抑制剂 K562 (IK) 蛋白首先从白血病细胞系 K562 的培养基中分离出来，是干扰素-γ 诱导的主要组织相容性复合物 II 类表达的抑制调节剂。最近，外源截短 IK (tIK) 蛋白显示出作为炎症相关疾病治疗剂的潜力。在这项研究中，我们基于人白细胞介素 (IL)-10 (hIL-10) 结构的同源模型，设计了一种源自 tIK 蛋白的新型推定抗炎肽，并研究了该肽是否对促炎细胞因子产生抑制作用如 IL-17 和肿瘤坏死因子-α (TNF-α)。该肽含有参与 hIL-10 与 IL-10 受体结合的关键残基，对 IL-17 (43.8%) 和 TNF-α (50.7%) 具有强烈的抑制作用。此外，我们使用圆二色光谱法来确认该肽通常以无规卷曲配置存在于水溶液中。就毒性而言，该肽被发现在生物学上是安全的。人tIK蛋白衍生的短肽对IL-17和TNF-α发挥抑制作用的机制有待进一步探讨。我们还评估了在护肤产品中使用这种新型肽的可行性。