Rheumatoid arthritis, caused by abnormalities in the autoimmune system, affects about 1% of the population. Rheumatoid arthritis does not yet have a proper treatment, and current treatment has various side effects. Therefore, there is a need for a therapeutic agent that can effectively treat rheumatoid arthritis without side effects. Recently, research on pharmaceutical drugs based on peptides has been actively conducted to reduce negative effects. Because peptide drugs are bio-friendly and bio-specific, they are characterized by no side effects. Truncated-IK (tIK) protein, a fragment of IK protein, has anti-inflammatory effects, including anti-rheumatoid arthritis activity. This study focused on the fact that tIK protein phosphorylates the interleukin 10 receptor. Through homology modeling with interleukin 10, short tIK epitopes were proposed to find the essential region of the sequence for anti-inflammatory activity. TH17 differentiation experiments were also performed with the proposed epitope. A peptide composed of 18 amino acids with an anti-inflammatory effect was named tIK-18mer. Additionally, a tIK 9-mer and a 14-mer were also found. The procedure for the experimental expression of the proposed tIK series (9-mer, 14-mer, and 18-mer) using bacterial strain is discussed.

中文翻译：

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作为抗炎肽的截短 IK 蛋白 tIK 的同源建模和优化表达

由自身免疫系统异常引起的类风湿性关节炎影响约 1% 的人口。类风湿性关节炎还没有合适的治疗方法，目前的治疗方法有各种副作用。因此，需要一种能够有效治疗类风湿性关节炎且无副作用的治疗剂。最近，已积极进行基于肽的药物研究以减少负面影响。由于肽类药物具有生物友好性和生物特异性，因此具有无副作用的特点。截短的 IK (tIK) 蛋白是 IK 蛋白的一个片段，具有抗炎作用，包括抗类风湿性关节炎活性。该研究重点关注 tIK 蛋白磷酸化白细胞介素 10 受体这一事实。通过与白细胞介素 10 的同源建模，提出了短 tIK 表位来寻找抗炎活性序列的基本区域。还用提议的表位进行了 TH17 分化实验。一种由18个氨基酸组成的具有抗炎作用的肽被命名为tIK-18mer。此外，还发现了一个 tIK 9-mer 和一个 14-mer。讨论了使用细菌菌株对提议的 tIK 系列（9 聚体、14 聚体和 18 聚体）进行实验表达的程序。