A GH family 28 endo-polygalacturonase from the brown-rot fungus Fomitopsis palustris: Purification, gene cloning, enzymatic characterization and effects of oxalate
A GH family 28 endo-polygalacturonase from the brown-rot fungus Fomitopsis palustris: Purification, gene cloning, enzymatic characterization and effects of oxalate
复制标题
DOI：
10.1016/j.ijbiomac.2018.11.004
复制
发表时间：
2019-02-15
影响因子：
8.2
通讯作者：
Konno, Naotake
中科院分区：
文献类型：
--
作者：
Tanaka, Yuki;Suzuki, Tomohiro;Konno, Naotake
褐腐菌是一类能分解植物细胞壁碳水化合物的木材腐朽菌。有人认为，果胶的降解是重要的褐腐病的初始阶段。从褐腐真菌沼泽拟层孔菌（Fomitopsis palustris）中分离纯化了一种内切多聚半乳糖醛酸酶（FpPG 28 A），氨基酸序列分析表明，FpPG 28 A属于GH家族28。纯化的FpPG 28 A的最高活性在60 ℃下在50 mM乙酸钠缓冲液（pH 5.0）中观察到;该活性对聚半乳糖醛酸链具有高度特异性。然而，在这些最佳条件下，聚半乳糖醛酸钙凝胶不被FpPG 28 A降解。我们观察到聚半乳糖醛酸钙凝胶在草酸盐缓冲液中很容易被酶降解。此外，在pH 3.0的草酸盐缓冲液中，FpPG 28 A的热稳定性提高。这些结果表明草酸盐在FpPG 28 A降解木质果胶过程中起重要作用。(C)2018 Elsevier B. V.版权所有。
Brown-rot fungi are the wood-decay basidiomycetes and have ability to break down plant cell wall carbohydrates. It has been suggested that degradation of pectin is important for the initial stages of brown rot. We purified an endo-polygalacturonase (FpPG28A) from the brown-rot fungus Fomitopsis palustris, analysis of the predicted amino acid sequence indicated that FpPG28A belongs to GH family 28. The highest activity of purified FpPG28A was observed at 60 degrees C in 50 mM sodium acetate buffer (pH 5.0); this activity was highly specific for polygalacturonic acid chains. However, calcium polygalacturonate gel was not degraded by FpPG28A under those optimal conditions. We observed that calcium polygalacturonate gel was readily degraded by the enzyme in the oxalate buffer. Furthermore, the thermostability of FpPG28A was elevated in oxalate buffer at pH 3.0. These results indicated that oxalate has an important role in the degradation of woody pectin by FpPG28A. (C) 2018 Elsevier B.V. All rights reserved.