Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, People's Republic of China.
Appl Biochem Biotechnol. 2012 Nov;168(6):1489-500. doi: 10.1007/s12010-012-9872-8. Epub 2012 Sep 15.
Alkaline pectate lyases are favorable for the textile industry. Here, we report the gene cloning and expression of a low-temperature-active alkaline pectate lyase (PL D) from Xanthomonas campestris ACCC 10048. Deduced PL D consists of a putative 27-residue signal peptide and a catalytic domain of 320 residues belonging to family PF09492. Recombinant PL D (r-PL D) produced in Escherichia coli was purified to electrophoretic homogeneity with a single step of Ni(2+)-NTA affinity chromatography and showed an apparent molecular weight of ~38 kDa. The pH and temperature optima of r-PL D were found to be 9.0 °C and 30 °C, respectively. Compared with its microbial counterparts, r-PL D had higher activity over a wide pH range (>45 % of the maximum activity at pH 3.0-12.0) and at lower temperatures (>35 % of activity even at 0 °C). The K(m) and V(max) values of r-PL D for polygalacturonic acid were 4.9 gl(-1) and 30.1 μmolmin(-1) mg(-1), respectively. Compared with the commercial compound pectinase from Novozymes, r-PL D showed similar efficacy in reducing the intrinsic viscosity of polygalacturonic acid (35.1 % vs. 36.5 %) and in bioscouring of jute (10.25 % vs. 10.82 %). Thus, r-PL D is a valuable additive candidate for the textile industry.
碱性果胶裂解酶对纺织工业有利。在这里，我们报告了来自黄单胞菌 ACCC 10048 的低温活性碱性果胶裂解酶（PL D）的基因克隆和表达。推导的 PL D 由一个假定的 27 个残基信号肽和属于家族 PF09492 的 320 个残基的催化结构域组成。在大肠杆菌中产生的重组 PL D（r-PL D）通过 Ni（2+）-NTA 亲和层析一步法纯化至电泳均一性，显示出约 38 kDa 的明显分子量。发现 r-PL D 的 pH 和温度最适值分别为 9.0°C 和 30°C。与微生物对应物相比，r-PL D 在较宽的 pH 范围内（在 pH 3.0-12.0 时具有>45％的最大活性）和较低的温度下（甚至在 0°C 时仍具有>35％的活性）具有更高的活性。r-PL D 对聚半乳糖醛酸的 K m 和 V max 值分别为 4.9 gl（-1）和 30.1 μmolmin（-1）mg（-1）。与诺维信的商业复合果胶酶相比，r-PL D 在降低聚半乳糖醛酸的固有粘度方面（35.1％对 36.5％）和在黄麻生物精炼方面（10.25％对 10.82％）表现出相似的效果。因此，r-PL D 是纺织工业有价值的添加剂候选物。
