Optimal covalent immobilization of glucose oxidase‐containing liposomes for highly stable biocatalyst in bioreactor
Optimal covalent immobilization of glucose oxidase‐containing liposomes for highly stable biocatalyst in bioreactor
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含葡萄糖氧化酶脂质体的最佳共价固定化，用于生物反应器中高度稳定的生物催化剂
DOI：
10.1002/bit.10684
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发表时间：
2003
影响因子：
3.8
通讯作者：
K. Nakao
中科院分区：
文献类型：
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作者：
Shaoqing Wang;M. Yoshimoto;K. Fukunaga;K. Nakao
含葡萄糖氧化酶的脂质体（GOL）是通过将葡萄糖氧化酶（GO）包埋在由磷脂酰胆碱（PC）、二肉豆蔻酰L-α-磷脂酰乙醇胺（DMPE）和胆固醇（Chol）组成的脂质体中而制备的，然后共价固定在戊二醛活化的壳聚糖凝胶珠中。对固定化GOL凝胶珠（IGOL）进行表征，以获得适用于生物反应器的高度稳定的生物催化剂。首先，对凝胶珠活化所用的戊二醛浓度以及固定化温度和时间进行优化，以最大程度地提高GOL的固定化产率。然后优化脂质体膜组成和脂质体尺寸，以获得最大可能的 GOL 固定产率、最高可能的 IGOL 活性效率以及在 GOL 固定期间尽可能低的包埋 GO 泄漏。结果发现最佳固定化条件为：脂质体组合物PC/DMPE/Chol=65/5/30(摩尔百分比)；脂质体尺寸，100 nm；戊二醛浓度，2%（w/v）；固定温度，4℃；固定时间10小时。此外，制备的最佳IGOL的特点是，随着温度从20°C升高到40°C，其对外部添加的底物（葡萄糖）的有效GO活性迅速增加，并且在40°C下具有高稳定性，不仅可以抵抗长期（7天）孵育中的热变性，还可以抵抗气泡柱中的鼓泡应力。最后，与传统固定化葡萄糖氧化酶（IGO）相比，通过在小型气升式生物反应器中重复（4次）或长时间（7天）催化葡萄糖氧化，验证了最佳IGOL具有更高的运行稳定性。 © 2003 Wiley periodicals, Inc. 生物技术 Bioeng 83: 444–453, 2003。
The glucose oxidase‐containing liposomes (GOL) were prepared by entrapping glucose oxidase (GO) in the liposomes composed of phosphatidylcholine (PC), dimyristoyl L‐α‐phosphatidylethanolamine (DMPE), and cholesterol (Chol) and then covalently immobilized in the glutaraldehyde‐activated chitosan gel beads. The immobilized GOL gel beads (IGOL) were characterized to obtain a highly stable biocatalyst applicable to bioreactor. At first, the glutaraldehyde concentration used in the gel beads activation as well as the immobilizing temperature and time were optimized to enhance the immobilization yield of the GOL to the highest extent. The liposome membrane composition and liposome size were then optimized to obtain the greatest possible immobilization yield of the GOL, the highest possible activity efficiency of the IGOL, and the lowest possible leakage of the entrapped GO during the GOL immobilization. As a result, the optimal immobilization conditions were found to be as follows: the liposome composition, PC/DMPE/Chol = 65/5/30 (molar percentage); the liposome size, 100 nm; the glutaraldehyde concentration, 2% (w/v); the immobilizing temperature, 4°C; and the immobilizing time, 10 h. Furthermore, the optimal IGOL prepared were characterized by its rapidly increasing effective GO activity to the externally added substrate (glucose) with increasing temperature from 20 to 40°C, and also by its high stability at 40°C against not only the thermal denaturation in a long‐term (7 days) incubation but also the bubbling stress in a bubble column. Finally, compared to the conventionally immobilized glucose oxidase (IGO), the higher operational stability of the optimal IGOL was verified by using it either repeatedly (4 times) or for a long time (7 days) to catalyze the glucose oxidation in a small‐scale airlift bioreactor. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 444–453, 2003.
磷脂双层的曲率和胆固醇含量改变了磷脂酰乙醇胺特定分子种类的跨双层分布。
DOI：
10.1080/09687680050197383
发表时间：
2000
期刊：
Molecular membrane biology.
影响因子：
--
作者：
Williams,EE;Cooper,JA;Stillwell,W;Jenski,LJ
通讯作者：
Jenski,LJ