Tang Hengmin, Sakamura Yuki, Mori Takeshi, Katayama Yoshiki, Kishimura Akihiro
Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka, 819-0395, Japan.
Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka, 819-0395, Japan.
Macromol Biosci. 2017 Aug;17(8). doi: 10.1002/mabi.201600542. Epub 2017 May 19.
Applications of enzymes are intensively studied, particularly for biomedical applications. However, encapsulation or immobilization of enzymes without deactivation and long-term use of enzymes are still at issue. This study focuses on the polymeric vesicles "PICsomes" for encapsulation of enzymes to develop a hecto-nanometer-scaled enzyme-loaded reactor. The catalytic activity of a PICsome-based enzyme nanoreactor is carefully examined to clarify the effect of compartmentalization by PICsome. Encapsulation by PICsome provides a stability enhancement of enzymes after 24 h incubation at 37 °C, which is particularly helpful for maintaining the high effective concentration of β-galactosidase. Moreover, to control the microenvironment inside the nanoreactor, a large amount of dextran, a neutral macromolecule, is encapsulated together with β-galactosidase in the PICsome. The resulting dextran-coloaded nanoreactor contributes to the enhancement of enzyme stability, even after exposure to 24 h incubation at -20 °C, mainly due to the antifreezing effect.
酶的应用正在深入研究，尤其是在生物医学应用方面。然而，酶的无失活封装或固定以及酶的长期使用仍然存在问题。本研究聚焦于用于酶封装的聚合物囊泡“聚离子复合物囊泡”，以开发一种百纳米级的载酶反应器。对基于聚离子复合物囊泡的酶纳米反应器的催化活性进行了仔细研究，以阐明聚离子复合物囊泡分隔作用的影响。聚离子复合物囊泡封装在37℃孵育24小时后可提高酶的稳定性，这对于维持β-半乳糖苷酶的高有效浓度特别有帮助。此外，为了控制纳米反应器内部的微环境，大量的葡聚糖（一种中性大分子）与β-半乳糖苷酶一起封装在聚离子复合物囊泡中。所得的共载葡聚糖纳米反应器即使在-20℃孵育24小时后也有助于提高酶的稳定性，这主要归因于抗冻作用。
