Chitin and its derivatives have anticoagulant, antimicrobial, and antioxidant properties, but the poor solubility of chitin limits its application in different fields. In this study, site-directed mutagenesis was performed to enhance the deacetylation activity of chitin deacetylases CDA from Arthrobacter (ArCE4). The mutant Mut-2-8 with Y172E/E200S/Y201W showed a 2.84- fold and 1.39-fold increase in catalytic efficiency (kcat/Km) for the deacetylation of (GluNAc)₅ and α-chitin, respectively. These results demonstrated that the mutations significantly improved the activation of ArCE4 on crystalline chitin. The molecular docking study confirmed that the enhancement of catalytic efficiency is due to the extra two hydrogen bonds and one acetyl group. In summary, the activity of Mut-2-8 to insoluble chitin was significantly improved by reactional design, which is beneficial to resolve the issues of the expensive cost of the enzymes and low efficiency. Mut-2-8 exhibits potential applications in the chitosan industry.

甲壳素及其衍生物具有抗凝血、抗菌、抗氧化等特性，但甲壳素溶解性差，限制了其在不同领域的应用。在这项研究中，进行了定点诱变以增强节杆菌（Ar CE4）的几丁质脱乙酰酶 CDA 的脱乙酰活性。具有 Y172E/E200S/Y201W 的突变体 Mut-2-8 对 (GluNAc) ₅和 α-几丁质的脱乙酰化的催化效率 (kcat/Km) 分别提高了 2.84 倍和 1.39 倍。这些结果表明，这些突变显着提高了Ar的活化结晶甲壳质上的 CE4。分子对接研究证实，催化效率的提高是由于多了两个氢键和一个乙酰基。综上所述，反应设计显着提高了Mut-2-8对不溶性几丁质的活性，有利于解决酶成本高、效率低的问题。Mut-2-8 展示了在壳聚糖工业中的潜在应用。