A Protein-Capsid-Based System for Cell Delivery of Selenocysteine.
A Protein-Capsid-Based System for Cell Delivery of Selenocysteine.
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DOI：
10.1021/acs.bioconjchem.8b00302
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发表时间：
2018-06
影响因子：
4.7
通讯作者：
Shuxin Wang;Aneesa T. Al-Soodani;G. C. Thomas;B. A. Buck-Koehntop;K. J. Woycechowsky
中科院分区：
文献类型：
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作者：
Shuxin Wang;Aneesa T. Al-Soodani;G. C. Thomas;B. A. Buck-Koehntop;K. J. Woycechowsky
硒代半胱氨酸（Sec）作为一种潜在的抗癌药物受到了广泛的关注。然而，其广泛的细胞毒性限制了其治疗用途。因此，Sec是靶向药物递送的有吸引力的候选者。在这里，我们第一次证明了由风产液菌荧光素合酶（AaLS）形成的衣壳的工程化版本可以充当用于将Sec递送到细胞的纳米载体。具体地，先前报道的AaLS变体（AaLS-IC）（其每个亚基含有单个半胱氨酸，其投射到衣壳内部）通过与Sec的二硒醚二聚体（Sec 2）反应来修饰，以在衣壳和Sec之间产生硒基硫化物缀合物（AaLS-IC-Sec）。重要的是，确定了反应性半胱氨酸的结构背景对于有效的衣壳装载是重要的。此外，包封的Sec可以通过还原剂如谷胱甘肽或二硫苏糖醇从AaLS-IC-Sec定量释放。为了评估AaLS-IC-Sec的细胞迁移能力和随后的细胞毒性应答，检查了六种不同的细胞系模型。在分析的细胞系中，细胞毒性敏感性与细胞摄取和细胞内运输模式相关。总之，这些发现表明，工程化的AaLS-IC衣壳是用于Sec的靶向细胞递送的有希望的载体。
Selenocysteine (Sec) has received a lot of attention as a potential anticancer drug. However, its broad cytotoxicity limits its therapeutic usefulness. Thus, Sec is an attractive candidate for targeted drug delivery. Here, we demonstrate for the first time that an engineered version of the capsid formed by Aquifex aeolicus lumazine synthase (AaLS) can act as a nanocarrier for delivery of Sec to cells. Specifically, a previously reported variant of AaLS (AaLS-IC), which contains a single cysteine per subunit that projects into the capsid interior, was modified by reaction with the diselenide dimer of Sec (Sec2) to generate a selenenylsulfide conjugate between the capsid and Sec (AaLS-IC-Sec). Importantly, it was determined that the structural context of the reactive cysteine was important for efficient capsid loading. Further, the encapsulated Sec could be quantitatively released from AaLS-IC-Sec by reducing agents such as glutathione or dithiothreitol. To assess cellular penetrance capabilities of AaLS-IC-Sec and subsequent cytotoxic response, six different cells line models were examined. Across the cell lines analyzed, cytotoxic sensitivity correlated with cellular uptake and intracellular trafficking patterns. Together these findings suggest that the engineered AaLS-IC capsid is a promising vehicle for targeted cell delivery of Sec.