Faculty of Science and Letters, Department of Chemistry, Yildiz Technical University, Istanbul, Turkey.
Faculty of Chemical & Metallurgical Engineering, Department of Bioengineering, Yildiz Technical University, Istanbul, Turkey.
Prep Biochem Biotechnol. 2020;50(6):572-577. doi: 10.1080/10826068.2020.1719515. Epub 2020 Jan 31.
In this study, the different mole ratios of glucose oxidase/chitosan/dextran-aldehyde and glucose oxidase/chitosan/dextran-sulfate complexes were synthesized. The modification of glucose oxidase by non-covalent complexation with dextran and chitosan in different molar ratios was studied in order to increase the enzyme activity. The enzyme/polymer complexes obtained were investigated by UV spectrophotometer and dynamic light scattering. Activity determination of synthesized complexes and free enzyme were performed at a temperature range. The best results were obtained by / = 10/1 ratio and / = 1/5 ratio that were used in thermal stability, shelf life, salt stress, and ethanol effect experiments. The results demonstrated that both complexes were thermally stable at 60 °C and had superior storage stability compared to the free glucose oxidase. Complexes showed higher enzymatic activity than free enzyme in the organic solvent environment using 10% ethanol. The complexes were resistant to salt stress containing 0.1 M NaCl or CaCl. The particle size distribution results of the triple complex evaluated the complexation of the chitosan, dextran derivative, and glucose oxidase. The average size of the triple complex in diameter was found to be 325.8 ± 9.3 nm. Overall findings suggest that the complexes of glucose oxidase, chitosan, and dextran showed significant enhancement in the enzyme activity.
在这项研究中，合成了葡萄糖氧化酶/壳聚糖/葡聚糖醛和葡萄糖氧化酶/壳聚糖/葡聚糖硫酸酯复合物的不同摩尔比。研究了通过非共价络合在不同摩尔比的葡聚糖和壳聚糖上修饰葡萄糖氧化酶，以提高酶活性。通过紫外分光光度计和动态光散射研究了所得酶/聚合物复合物。在一定温度范围内测定了合成复合物和游离酶的活性。/ = 10/1 比和/ = 1/5 比的最佳结果用于热稳定性、保质期、盐胁迫和乙醇效应实验。结果表明，两种复合物在 60°C 下均具有热稳定性，与游离葡萄糖氧化酶相比具有更好的储存稳定性。在有机溶剂环境中使用 10%乙醇时，复合物的酶活性高于游离酶。复合物在含有 0.1M NaCl 或 CaCl 的盐胁迫下具有抗性。对壳聚糖、葡聚糖衍生物和葡萄糖氧化酶的三元复合物的粒径分布结果进行了评价。发现三元复合物的平均粒径为 325.8±9.3nm。总体研究结果表明，葡萄糖氧化酶、壳聚糖和葡聚糖的复合物显著提高了酶活性。
