在人体/化物共载体 (NIS) 中工程基质选择性.
bioRxiv : the preprint server for biology
|November 24, 2025
概括
工程化Na+/I−共载体 (NIS) 突变物选择性地运输氧离子,而不是化物. 这允许使用放射性同位素进行向癌症治疗,同时保护甲状腺,扩大NIS应用范围超出甲状腺癌治疗范围.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- Na+/I−共载体 (NIS) 对于甲状腺激素的合成和甲状腺癌的放射性化物治疗至关重要.
- 非甲状腺癌中的外源性NIS表达提供了向治疗潜力,但有可能损害甲状腺.
- 需要一种策略来选择性地准表达NIS的癌症,同时不影响甲状腺.
研究的目的:
- 为向癌症治疗设计一种具有改变基质特异性的新型NIS变体.
- 调查NIS中基质选择性的结构基础.
- 开发一种选择性杀死癌细胞的方法,使用工程NIS和放射性同位素.
主要方法:
- 蛋白质工程创造了一个双重突变的NIS (L253P/V254F,或PF-NIS).
- 低温电子显微镜 (cryo-EM) 用于确定与酸盐和离子结合的PF-NIS的结构.
- 基于细胞的测试,以评估化物和氧化离子的运输和细胞活力.
主要成果:
- 设计的PF-NIS有选择性地运输氧离子 (例如,酸盐),但不运输化物.
- 低温电磁探测器以2.58 Å分辨率揭示了PF-NIS的结构,其中含有结合的酸和离子.
- PF-NIS表达细胞被放射性酸杀死,而非放射性酸保护了野生型NIS表达细胞.
结论:
- 工程 PF-NIS 允许选择性向非甲状腺癌,使用放射性同位素如 186/188ReO4−.
- 这种方法可以在保护甲状腺的同时进行向的癌症破坏.
- 该研究为开发基于NIS的疗法提供了一个框架,为更广泛的临床应用提供了量身定制的基质特异性.
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