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水稻纹枯病菌产生的多聚半乳糖醛酸酶(Polygalacturonase,PG)是其重要的致病因子之一。用丙酮法提取PG粗蛋白,分别经DEAE-Sepharose Fast Flow离子交换柱、Phenyl-Sepharose 6 Fast Flow疏水柱、Sephadex G-75凝胶柱和DE52离子交换柱层析纯化得到一种具有较高活性的PG纯蛋白。该蛋白分子量为39.81 kD;等电点为4.58;含有糖基,含糖量为1.48%;含有α氨基酸,但不含芳香族氨基酸;不含脂基。这种蛋白在pH4~12范围内均具有活性,pH5时活性最大;对热不稳定,100℃下水浴20 min,活性完全丧失;对胰蛋白酶和蛋白酶K敏感,酶处理后其活性只有对照的35.0%和35.2%;对紫外线和氯仿亦敏感,处理后活性仅为对照的40.0%和51.7%。
Polygalacturonase (PG) produced by Rhizoctonia solani is one of the important virulence factors. The crude PG protein was extracted by acetone method and purified by DEAE-Sepharose Fast Flow ion exchange column, Phenyl-Sepharose 6 Fast Flow hydrophobic column, Sephadex G-75 gel column and DE52 ion exchange column. Of PG pure protein. The molecular weight of the protein is 39.81 kD; the isoelectric point is 4.58; contains a glycosyl group with a sugar content of 1.48%; contains alpha amino acids but no aromatic amino acids; The activity of this protein was in the range of pH4 ~ 12 and the activity was the highest at pH5. The activity was completely lost when it was heated in water bath at 100 ℃ for 20 min, and it was sensitive to trypsin and proteinase K. The enzyme activity was only controlled 35.0% and 35.2% respectively. It was also sensitive to UV and chloroform, and its activity after treatment was only 40.0% and 51.7% of the control.