Various hydrophobic supports have been used for lipase immobilization since the active site of lipase can be opened in a hydrophobic environment. Nevertheless, the increase of lipase activity is still limited. This study demonstrates a hyperactivation-protection strategy of lipase after immobilization on poly(n-butyl acrylate)–polyaldehyde dextran (PBA–PAD) core–shell nanoparticles. The inner hydrophobic PBA domain helps to rearrange lipase conformation to a more active form after immobilization into the PAD shell. More importantly, the outer PAD shell with dense polysaccharide chains prevents the immobilized lipase from contacting with outside aqueous medium and reverting its conformation back to an inactive form. As a result, under optimal conditions the activity of lipase immobilized in PBA–PAD nanoparticles was enhanced 40 times over the free one, much higher than in any previous report. Furthermore, the immobilized lipase retained more than 80% of its activity after 10 reaction cycles.

中文翻译：

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开放盖子的保护：固定在核壳纳米粒子上的脂肪酶具有很高的催化活性

由于可以在疏水性环境中打开脂肪酶的活性位点，因此已将各种疏水性支持物用于脂肪酶的固定化。然而，脂肪酶活性的增加仍然是有限的。该研究证明了固定在聚（n）上的脂肪酶的超活化保护策略。丙烯酸丁酯）-聚甲醛右旋糖酐（PBA-PAD）核-壳纳米粒子。固定在PAD壳中后，内部疏水性PBA结构域有助于将脂肪酶构象重新排列为更具活性的形式。更重要的是，具有密集多糖链的PAD外壳可防止固定化脂肪酶与外部水性介质接触，并将其构象恢复为非活性形式。结果，在最佳条件下，固定在PBA-PAD纳米颗粒中的脂肪酶活性比游离的脂肪酶增强40倍，远高于以前的任何报道。此外，固定的脂肪酶在10个反应循环后仍保留了80％以上的活性。