Wu Pan, Luo Feifan, Lu Zhenghui, Zhan Zhichun, Zhang Guimin
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, China.
Wuhan Sunhy Biology Co., Ltd., Wuhan, China.
Front Bioeng Biotechnol. 2020 Apr 3;8:280. doi: 10.3389/fbioe.2020.00280. eCollection 2020.
Pectate lyases (Pels) can be used in the textile industrial process for cotton scouring and ramie degumming, and its hydrolyzed products oligo galacturonic acid, are high-value added agricultural and health products. In our previous studies, an alkaline pectate lyase PEL168 mutant, PEL3, was obtained with improved specific activity and thermostability. Here, a facile and rapid method for preparing an immobilized PEL3-inorganic hybrid nanoflower was developed, as it could improve its biocatalytic performance. With 0.02 mg/mL (112.2 U/mL) PEL3 in PBS buffer, five different divalent ions, including Mn, Ca, Co, Zn, and Cu, were used as inorganic component. The results showed that PEL3/Cu(PO) hybrid nanoflowers presented the highest relative activity with 2.5-fold increase, compared to the free PEL3. X-ray diffraction analysis confirmed that the composition of PEL3/Cu(PO) hybrid nanoflowers were pectate lyase PEL3 and Cu(PO)⋅5HO. The optimum temperature and pH of PEL3/Cu(PO) hybrid nanoflowers were ascertained to be 55°C and pH 9.0, respectively, exhibiting subtle difference from the free PEL3. However, the PEL3/Cu(PO) hybrid nanoflowers maintained 33% residual activity after 24 h incubation at 55°C, while the free PEL3 completely lost its activity after 18 h incubation at 55°C. Furthermore, over 50% residual activity of the PEL3/Cu(PO) hybrid nanoflowers was remained, even after four times of repetitive utilization, demonstrating its promising stability for practical application.
果胶酸裂解酶（Pels）可用于纺织工业中的棉织物精练和苎麻脱胶过程，其水解产物低聚半乳糖醛酸是高附加值的农产品和保健品。在我们之前的研究中，获得了一种碱性果胶酸裂解酶PEL168突变体PEL3，其比活性和热稳定性得到了提高。在此，开发了一种简便快速的制备固定化PEL3-无机杂化纳米花的方法，因为它可以提高其生物催化性能。在PBS缓冲液中使用0.02 mg/mL（112.2 U/mL）的PEL3，将包括Mn、Ca、Co、Zn和Cu在内的五种不同二价离子用作无机组分。结果表明，与游离PEL3相比，PEL3/Cu(PO)杂化纳米花具有最高的相对活性，提高了2.5倍。X射线衍射分析证实，PEL3/Cu(PO)杂化纳米花的组成是果胶酸裂解酶PEL3和Cu(PO)⋅5HO。确定PEL3/Cu(PO)杂化纳米花的最佳温度和pH分别为55°C和pH 9.0，与游离PEL3相比有细微差异。然而，PEL3/Cu(PO)杂化纳米花在55°C孵育24小时后仍保持33%的残余活性，而游离PEL3在55°C孵育18小时后完全失去活性。此外，即使经过四次重复使用，PEL3/Cu(PO)杂化纳米花仍保留超过50%的残余活性，表明其在实际应用中具有良好的稳定性。
