In this study, a simple and efficient method to obtain entrapment of mixtures of double enzymes is developed. As a proof of principle, double enzymes (tyrosinase (TYR) and β-glucosidase (β-Glu)) were co-immobilized in magnetic alginate-polydopamine (PDA) beads using in situ TYR-mediated dopamine polymerization and internal setting strategy-mediated magnetic alginate-PDA gelation. The leakage of enzymes from the magnetic alginate beads was significantly reduced by exploiting the double network cross-linking of alginate and PDA, which was induced by the d-(+)-Gluconic acid δ-lactone (GDL) and TYR, respectively. The physicochemical properties of the prepared magnetic alginate beads were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. After that, the enzymatic reaction conditions and the performance of the entrapped TYR and β-Glu, such as enzyme kinetics and inhibition kinetics, were investigated. The Michaelis-Menten constants (Km) of the entrapped TYR and β-Glu were determined as 2.72 and 3.45 mM, respectively. The half-maximal inhibitory concentrations (IC50) of kojic acid and castanospermine for the entrapped TYR and β-Glu were determined as 13.04 and 56.23 μM, respectively. Finally, the entrapped double enzymes magnetic alginate beads were successfully applied to evaluate the inhibitory potency of six kinds of tea polyphenols extracts. Black tea and white tea showed high inhibition activity against TYR were (36.14 ± 1.43)% and (36.76 ± 2.35)%, respectively, while the black tea and dark tea showed high inhibition activity against β-Glu were (37.89 ± 6.70)% and (21.28 ± 4.68)%, respectively.

中文翻译：

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酪氨酸酶介导的多巴胺聚合修饰的藻酸盐磁珠，用于双酶封装：制备，性能和应用。

在这项研究中，开发了一种简单有效的方法来捕获双重酶混合物。作为原理上的证明，使用原位TYR介导的多巴胺聚合和内部设置策略介导的双酶（酪氨酸酶（TYR）和β-葡萄糖苷酶（β-Glu））共固定在藻酸盐-聚多巴胺（PDA）磁珠中。磁性藻酸盐-PDA凝胶化。通过利用藻酸盐和PDA的双网络交联，可显着减少酶从藻酸盐磁珠中的泄漏，这是分别由d-（+）-葡萄糖酸δ-内酯（GDL）和TYR诱导的。通过傅立叶变换红外光谱（FT-IR），X射线衍射（XRD）和扫描电子显微镜（SEM）分析表征了制备的藻酸盐磁性珠的理化性质。之后，考察了酶的反应条件和包埋的TYR和β-Glu的性能，如酶动力学和抑制动力学。截留的TYR和β-Glu的Michaelis-Menten常数（Km）分别确定为2.72和3.45 mM。曲酸和粟精胺对所捕获的TYR和β-Glu的半数最大抑制浓度（IC50）分别确定为13.04和56.23μM。最后，成功地将包埋的双酶磁性藻酸盐微珠应用于评价六种茶多酚提取物的抑菌效果。红茶和白茶对TYR的抑制活性分别为（36.14±1.43）％和（36.76±2.35）％，而红茶和黑茶对β-Glu的抑制活性分别为（37.89±6.70）％和（21.28±4.68）％，