National Institute of Advanced Industrial Science and Technology (AIST), Nigatake 4-2-1, Miyagino-ku, Sendai 983-8551, Japan.
Colloids Surf B Biointerfaces. 2010 Feb 1;75(2):478-82. doi: 10.1016/j.colsurfb.2009.09.022. Epub 2009 Sep 23.
We assembled a highly durable conjugate with both a high-density accumulation and a regular array of lipase, by encapsulating it in mesoporous silica (FSM) with alkyltrimethylammonium (CTAB) chains on the surface. The activity for hydrolyzing esters of the lipase immobilized in mesoporous silica was linearly related to the concentration of lipase, whereas that of non-immobilized lipase showed saturation due to self-aggregation at a high concentration. The lipase conjugate also had increased resistance to heating when stayed in the silica coupling with CTAB. In addition, encapsulating the enzyme with FSM coupled CTAB caused the lipase to remain stable even in the presence of urea and trypsin, suggesting that the encapsulation prevented dissociation and denaturing. This conjugate had much higher activity and much higher stability for hydrolyzing esters when compared to the native lipase. These results show that FSM provides suitable support for the immobilization and dispersion of proteins in mesopores with disintegration of the aggregates.
我们通过将其包裹在具有表面烷基三甲基铵（CTAB）链的介孔硅（FSM）中，组装了一种具有高密度积累和规则排列的脂肪酶的高耐用性缀合物。固定在介孔硅中的脂肪酶水解酯的活性与脂肪酶的浓度呈线性关系，而未固定的脂肪酶的活性由于在高浓度下的自聚集而表现出饱和。当与 CTAB 偶联的硅中存在时，固定化脂肪酶的酶缀合物的耐热性也得到了提高。此外，用 FSM 包裹与 CTAB 偶联的酶可使脂肪酶即使在存在脲和胰蛋白酶的情况下也保持稳定，表明封装防止了解离和变性。与天然脂肪酶相比，该缀合物在水解酯时具有更高的活性和更高的稳定性。这些结果表明，FSM 为蛋白质在介孔中的固定和分散提供了合适的支撑，同时可防止聚集物的解体。
