Papain (PA) immobilized onto magnetic nanocrystalline cellulose (PA@MNCC) was successfully fabricated and adopted as an efficient biocatalyst for the synthesis of N-(benzyloxycarbonyl)-alanyl-histidine (Z-Ala-His) dipeptide. Introducing deep eutectic solvents (DESs) as reaction media promoted the synthesis of the Z-Ala-His dipeptide. The effects of reaction conditions on the yield of papain catalytic Z-Ala-His were systematically investigated with the highest yield of 68.4%, which was higher than free papain (63.3%). Besides, this novel PA@MNCC composite can be easily recycled from the reaction system by magnetic forces. In a word, the PA@MNCC composite exhibited great potential for efficient biosynthesis of dipeptide in DESs.

成功地制备了固定在磁性纳米晶体纤维素（PA @ MNCC）上的木瓜蛋白酶（PA），并将其用作合成N-（苄氧羰基）-丙氨酰-组氨酸（Z-Ala-His）二肽的有效生物催化剂。引入深共熔溶剂（DESs）作为反应介质可促进Z-Ala-His二肽的合成。系统研究了反应条件对木瓜蛋白酶催化Z-Ala-His产率的影响，最高产率为68.4％，高于游离木瓜蛋白酶（63.3％）。此外，这种新型的PA @ MNCC复合材料可以很容易地通过磁力从反应系统中回收。简而言之，PA @ MNCC复合材料在DES中高效生物合成具有巨大的潜力。