Abstract Lecitase Ultra (Leci) was immobilized on Immobead-350 (IB-350) activated with epoxy (EPO), amino-divinylsulfone (DVS) or amino-glutaraldehyde (GLU) groups. Leci-GLU had 27% more activity versus p-nitro-phenyl butyrate (p-NPB) than Leci-EPO, after 3 h of immobilization using 100 mg of enzyme/g of support (immobilization yield was 84.1%, expressed activity versus p-NPB was around 10%), the covalent immobilization was show for Leci-GLU and Leci-DVS. After 10 consecutive cycles of p-NPB hydrolysis, its activity remained unaltered. Leci-GLU was the most stable preparation at 65 °C and pH 7 (29 folds more stable than the free enzyme) and in the presence of 30% acetonitrile at 30 °C and pH 7 (almost 2 folds more stable than the free enzyme). Very interestingly, the activity versus methyl mandelate and synthesis of benzyl acetate was quite high. Although the other biocatalysts had preference for the S-methyl mandelate, Leci-GLU preferred the R-isomer at pHs 5 (VR/VS = 6.6) and 7 (VR/VS = 3.5). In the enzymatic synthesis of benzyl acetate, the most active biocatalyst was also Leci-GLU (2.1 U/mg), being almost 2 folds more active than Leci-DVS. According to the results, it was concluded that the Lecitase immobilization on IB-350 using different chemistries greatly influenced its catalytic properties.

中文翻译：

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通过固定在不同活化的 Immobead-350 上调节 Lecitase 特性：对映特异性的稳定化和反转

摘要 Lecitase Ultra (Leci) 固定在用环氧树脂 (EPO)、氨基二乙烯基砜 (DVS) 或氨基戊二醛 (GLU) 基团活化的 Immobead-350 (IB-350) 上。使用 100 mg 酶/g 载体固定 3 小时后，Leci-GLU 与对硝基苯基丁酸酯 (p-NPB) 相比活性高出 27%（固定产率为 84.1%，表达活性与 p -NPB 约为 10%），Leci-GLU 和 Leci-DVS 显示出共价固定。p-NPB 水解连续 10 个循环后，其活性保持不变。Leci-GLU 在 65 °C 和 pH 7（比游离酶稳定 29 倍）和 30% 乙腈存在下在 30 °C 和 pH 7（比游离酶稳定近 2 倍）下是最稳定的制剂）。非常有趣的是，相对于扁桃酸甲酯的活性和乙酸苄酯的合成相当高。尽管其他生物催化剂偏爱 S-扁桃酸甲酯，但 Leci-GLU 在 pH 值为 5 (VR/VS = 6.6) 和 7 (VR/VS = 3.5) 时更喜欢 R-异构体。在乙酸苄酯的酶促合成中，活性最强的生物催化剂也是 Leci-GLU (2.1 U/mg)，其活性几乎是 Leci-DVS 的 2 倍。根据结果​​，可以得出结论，使用不同化学物质将 Lecitase 固定在 IB-350 上对其催化性能有很大影响。