在中过表达和生化特性分析内切α-1,4-多聚半乳糖醛酸酶。

Overexpression and Biochemical Characterization of an Endo-α-1,4-polygalacturonase from in .

机构信息

Jiangxi Agricultural University, College of Bioscience and Bioengineering, Nanchang 330045, China.

Sichuan Normal University, College of Life Science, Chengdu 610101, China.

出版信息

Int J Mol Sci. 2020 Mar 19;21(6):2100. doi: 10.3390/ijms21062100.

Pectinases have many applications in the industry of food, paper, and textiles, therefore finding novel polygalacturonases is required. Multiple sequence alignment and phylogenetic analysis of AnEPG (an endo-α-1,4-polygalacturonase from ) and other GH 28 endo-polygalacturonases suggested that AnEPG is different from others. AnEPG overexpressed in was characterized. AnEPG showed the highest activity at pH 4.0, and exhibited moderate activity over a narrow pH range (pH 2.0-5.0) and superior stability in a wide pH range (pH 2.0-12.0). It displayed the highest activity at 60 °C, and retained >42.2% of maximum activity between 20 and 80 °C. It was stable below 40 °C and lost activity very quickly above 50 °C. Its apparent kinetic parameters against PGA (polygalacturonic acid) were determined, with the and values of 8.3 mg/mL and 5640 μmol/min/mg, respectively. Ba and Ni enhanced activity by 12.2% and 9.4%, respectively, while Ca, Cu, and Mn inhibited activity by 14.8%, 12.8%, and 10.2% separately. Analysis of hydrolysis products by AnEPG proved that AnEPG belongs to an endo-polygalacturonase. Modelled structure of AnEPG by I-TASSER showed structural characteristics of endo-polygalacturonases. This pectinase has great potential to be used in food industry and as feed additives.

果胶酶在食品、造纸和纺织工业中有许多应用，因此需要寻找新型的聚半乳糖醛酸酶。对 AnEPG（来自的内切-α-1,4-聚半乳糖醛酸酶）和其他 GH28 内切聚半乳糖醛酸酶的多重序列比对和系统发育分析表明，AnEPG 与其他酶不同。在中过表达的 AnEPG 进行了表征。AnEPG 在 pH4.0 时表现出最高的活性，在较窄的 pH 范围内（pH2.0-5.0）表现出中等活性，在较宽的 pH 范围内（pH2.0-12.0）表现出较高的稳定性。它在 60°C 时表现出最高的活性，在 20-80°C 之间保留了>42.2%的最大活性。它在低于 40°C 时稳定，在 50°C 以上迅速失去活性。测定了其对 PGA（聚半乳糖醛酸）的表观动力学参数，值和值分别为 8.3mg/mL 和 5640μmol/min/mg。Ba 和 Ni 分别提高了 12.2%和 9.4%的活性，而 Ca、Cu 和 Mn 则分别抑制了 14.8%、12.8%和 10.2%的活性。AnEPG 水解产物的分析证明 AnEPG 属于内切聚半乳糖醛酸酶。I-TASSER 对 AnEPG 结构的建模显示了内切聚半乳糖醛酸酶的结构特征。这种果胶酶在食品工业和饲料添加剂中有很大的应用潜力。