作者:Andrea Belluati、Ioana Craciun、Juan Liu、Cornelia G. Palivan
DOI:10.1021/acs.biomac.8b01019
日期:2018.10.8
Compartmentalization at the nanoscale is fundamental in nature, where the spatial segregation of biochemical reactions within cells ensures optimal conditions for regulating metabolic pathways. Here, we present a nature-inspired approach to engineer enzymatic cascade reactions taking place between separate vesicular nanocompartments (polymersomes), each containing one enzyme type. We propose, by the selected combination of enzymes, an efficient solution to detoxify the harmful effect of uric acid and prevent the accumulation of the derived H2O2, both being associated with various pathological conditions (e.g., gout and oxidative stress). Fungal uricase and horseradish peroxidase combined to act in tandem, and they were separately encapsulated within nanocompartments that were equipped with channel porins as gates to allow passage of substrates and products from each step of the reaction. We established the molecular factors affecting the efficiency of the overall reaction, and the protective role of the compartments. Interestingly, the cascade reaction between separate nanocompartments was as efficient as for free enzymes in complex media, such as human serum. The nanocompartments were nontoxic toward cells, and more importantly, addition of the tandem catalytic nanocompartments to cells exposed to uric acid provided simultaneous detoxification of uric acid and the H2O2. Such catalytic nanocompartments can be used as a platform for understanding fundamental factors affecting intracellular communication and can introduce non-native metabolic reactions into living systems for therapeutic applications.
纳米尺度的区室化本质上是基本的,细胞内生化反应的空间隔离确保了调节代谢途径的最佳条件。在这里,我们提出了一种受自然启发的方法来设计在单独的囊泡纳米室(聚合物囊泡)之间发生的酶级联反应,每个囊泡纳米室包含一种酶类型。我们提出,通过选定的酶组合,提供一种有效的解决方案来解毒尿酸的有害作用并防止衍生的 H2O2 的积累,这两者都与各种病理状况(例如痛风和氧化应激)有关。真菌尿酸酶和辣根过氧化物酶结合起来协同作用,它们被分别封装在纳米室中,纳米室配备有通道孔蛋白作为门,允许反应每个步骤的底物和产物通过。我们确定了影响整个反应效率的分子因素以及隔室的保护作用。有趣的是,单独的纳米室之间的级联反应与复杂介质(例如人血清)中的游离酶一样有效。纳米室对细胞无毒,更重要的是,将串联催化纳米室添加到暴露于尿酸的细胞中可以同时解毒尿酸和H2O2。这种催化纳米室可以用作了解影响细胞内通讯的基本因素的平台,并且可以将非天然代谢反应引入生命系统中以用于治疗应用。