Enzymatic rhamnosylation of anticancer drugs by an α-l-rhamnosidase from Alternaria sp. L1 for cancer-targeting and enzyme-activated prodrug therapy
Enzymatic rhamnosylation of anticancer drugs by an α-l-rhamnosidase from Alternaria sp. L1 for cancer-targeting and enzyme-activated prodrug therapy
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DOI：
10.1007/s00253-019-10011-0
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发表时间：
2019-08
影响因子：
5
通讯作者：
Li Xu;Xiaohong Liu;Yinping Li;Zhenhao Yin;Lan Jin;Lili Lu;Jingyao Qu;M. Xiao
中科院分区：
文献类型：
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作者：
Li Xu;Xiaohong Liu;Yinping Li;Zhenhao Yin;Lan Jin;Lili Lu;Jingyao Qu;M. Xiao
由于鼠李糖苷类化合物具有潜在的治疗应用价值，因此其合成具有重要的意义。生物活性分子糖基化的酶促方法已经得到了很好的发展，然而，由于缺乏鼠李糖基转移酶的糖基供体，酶促鼠李糖化反应在很大程度上受到了阻碍。在这里，我们使用了来自Alternarias.L1(RhaL1)的α-L-鼠李糖苷酶(RhaL1)来进行抗癌药物的一步鼠李糖化反应，包括2‘-脱氧-5-氟尿苷(FUDR)、阿糖胞苷(Ara C)和羟基脲(Hydrea)。通过对反应底物浓度和反应时间等关键合成条件的优化，鼠李糖苷类药物的最高产率分别为57.7、68.6和42.2 mmol。值得指出的是，这些鼠李糖基化药物对癌细胞几乎没有细胞毒作用，但与外源α-L-鼠李糖苷酶孵育后，可以有效地恢复细胞毒活性，提示它们在酶激活前药系统中的潜在应用。为了评价鼠李糖部分的肿瘤靶向性，构建了鼠李糖偶联荧光染料罗丹明B(Rha-RhB)。荧光探针Rha-RhB对口腔癌细胞KB和乳腺癌细胞MDA-MB-231的细胞亲和力和细胞内化率明显高于正常上皮细胞MCF 10A，提示鼠李糖部分可介导鼠李糖苷类化合物特异性内化进入癌细胞，极大地促进了它们在肿瘤靶向给药方面的应用。
The synthesis of rhamnosylated compounds has gained great importance since these compounds have potential therapeutic applications. The enzymatic approaches for glycosylation of bioactive molecules have been well developed; however, the enzymatic rhamnosylation has been largely hindered by lacking of the glycosyl donor for rhamnosyltransferases. Here, we employed an α-l-rhamnosidase fromAlternariasp.L1 (RhaL1) to perform one-step rhamnosylation of anticancer drugs, including 2′-deoxy-5-fluorouridine (FUDR), cytosine arabinoside (Ara C), and hydroxyurea (Hydrea). The key synthesis conditions including substrate concentrations and reaction time were carefully optimized, and the maximum yields of each rhamnosylated drugs were 57.7 mmol for rhamnosylated Ara C, 68.6 mmol for rhamnosylated Hydrea, and 42.2 mmol for rhamnosylated FUDR. It is worth pointing out that these rhamnosylated drugs exhibit little cytotoxic effects on cancer cells, but could efficiently restore cytotoxic activity when incubated with exogenous α-l-rhamnosidase, suggesting their potential applications in the enzyme-activated prodrug system. To evaluate the cancer-targeting ability of rhamnose moiety, the rhamnose-conjugated fluorescence dye rhodamine B (Rha-RhB) was constructed. The fluorescence probe Rha-RhB displayed much higher cell affinity and cellular internalization rate of oral cancer cell KB and breast cancer cell MDA-MB-231 than that of the normal epithelial cells MCF 10A, suggesting that the rhamnose moiety could mediate the specific internalization of rhamnosylated compounds into cancer cells, which greatly facilitated their applications for cancer-targeting drug delivery.