摘要
由于番茄成熟后很快变软,极难尿鲜和贮藏运输。采收的绿熟果实,用较先进的低温气调技术也只能贮存45天。早在60年代初指出多聚半乳糖醛酸酶与番茄果实软化密切相关,继后许多研究证明,该酶是一种细胞壁蛋白。
The polygalacturonase(PG)isolated from the pericarp of fully ripe tomato fruits was purified by(NH_4)_2SO_4 precipitation,carboxyme-thylsepharose ion-exchang column and se- phadex G-75 gel filtration.Specific activity of purified PG was 1.5μmol galacturonic acid mg^(-1)protein min^(-1),which was 30 times as high as that of the crude extract with 1.7mol NaCl. When the elution separated by second sephadex G-75 column was analyzed by SDS-PAGE, only a single protein band was detected.It was shown by heat and pH experiments of the pu- rified enzyme that the enzyme activity retained 50%,after treatment with heat at 50℃ for 10 min,and that the optimal pH was 4.6.
基金
国家自然科学基金资助课题
关键词
番茄
果实
纯化
PG
Tomatoes pericarp
Polygalacturonase
