Dipartimento di Scienza e Alta Tecnologia and INSTM udr Como, Insubria University, Via Valleggio 9, I-22100 Como, Italy.
Dipartimento di Chimica, Turin University, Via P. Giuria 7, I-10125 Turin, Italy.
Int J Mol Sci. 2019 Jun 18;20(12):2965. doi: 10.3390/ijms20122965.
Incorporation of biological systems in water nanodroplets has recently emerged as a new frontier to investigate structural changes of biomolecules, with perspective applications in ultra-fast drug delivery. We report on the molecular dynamics of the digestive protein Pepsin subjected to a double confinement. The double confinement stemmed from embedding the protein inside a water nanodroplet, which in turn was caged in a nanochannel mimicking the mesoporous silica SBA-15. The nano-bio-droplet, whose size fits with the pore diameter, behaved differently depending on the protonation state of the pore surface silanols. Neutral channel sections allowed for the droplet to flow, while deprotonated sections acted as anchoring piers for the droplet. Inside the droplet, the protein, not directly bonded to the surface, showed a behavior similar to that reported for bulk water solutions, indicating that double confinement should not alter its catalytic activity. Our results suggest that nanobiodroplets, recently fabricated in volatile environments, can be encapsulated and stored in mesoporous silicas.
生物系统在水纳米液滴中的结合最近成为研究生物分子结构变化的一个新前沿，具有超快速药物输送的应用前景。我们报告了受双重限制的消化蛋白胃蛋白酶的分子动力学。这种双重限制源于将蛋白质嵌入水纳米液滴中，而水纳米液滴又被模拟介孔二氧化硅 SBA-15 的纳米通道笼住。这种纳米生物液滴的大小与孔径相匹配，其行为取决于孔表面硅醇的质子化状态。中性通道部分允许液滴流动，而去质子化部分则充当液滴的锚固墩。在液滴内，未直接与表面键合的蛋白质表现出与在体相水溶液中报告的相似行为，表明双重限制不应改变其催化活性。我们的结果表明，最近在挥发性环境中制造的纳米生物液滴可以被封装并储存在介孔硅中。
