香蕉多聚半乳糖醛酸酶抑制蛋白的分离与纯化

Isolation and purification of a polygalacturonase-inhibiting protein from banana

多聚半乳糖醛酸酶抑制蛋白(PGIP)能够特异性结合并抑制真菌侵染所产生的多聚半乳糖醛酸酶。本试验以健康香蕉幼苗植株为材料,通过硫酸铵沉淀、PM10膜超滤浓缩、亲和层析、离子交换层析以及凝胶层析等步骤,纯化获得一种PGIP,SDS-PAGE确定其分子质量为38.2ku。该PGIP的活性对温度敏感,对香蕉枯萎病菌4号小种(Foc4)PG酶活性的抑制高于对Aspergillus niger PG酶活性的抑制,表明其对不同PG酶的抑制具有选择性。

Polygalacturonase-inhibiting protein（PGIP） is a cell wall binding protein that can specifically inhibit the activity of fungal polygalacturonase.A PGIP was purified from healthy banana seedlings by a series of column chromatography： ConA affinity column,CM-Sepharose ion exchange column and Sephadex S-100 gel filtration column.The 38.2 ku PGIP was shown as a single band,as determined by SDS-PAGE.Its activity is sensitive to different temperatures.The inhibition of the PGIP to Fusarium oxysporum f.sp.cubense race 4（Foc4） is higher than its inhibition to Aspergillus niger PG,which suggested the banana PGIP activity might specifically inhibit certain PG.