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番茄叶片胞外β-半乳糖苷酶的纯化和性质

史益敏, 颜季琼, 费雪南, 许煜泉

上海农学院植物科学系. 上海(201101)；华东师范大学生物系. 上海(200062)

摘要

系统感染TMV的番茄叶胞外提取液经冰冻干燥浓缩、-20℃丙酮沉淀、CM-SephadexC-25阳离子交换层析、DEAE-Sephadex A-25阴离子交换层析和SephadexG-150凝胶层析纯化,获得PAGE和SDS-PAGE均一的β-半乳糖苷酶。该酶的分子量为74kD,酶蛋白带能被过碘酸-Schiff试剂染成桃红色, 属糖蛋白,无论在健康或系统感染TMV的番茄叶中, 均为主要的胞外蛋白组分之一。图9表1参19

关键词： 番茄; 胞外蛋白; β－半乳糖苷酶; TMV

Purification and properties of #beta#-galactosidase from intercellular fluidof tomato leaves

Shi Yimin, Yan Jiqiong, Fei Xuenan, Xu Yuquan

Department of Plant Science, Shanghai Agricultural College.Shanghai；China(200062)

Abstract

High #beta#-galactosidase activity was found in the apoplastic spaces oftomato(Lycopersicon esculentum)leaves whether the plant was healthy orsystemically infected by TMV. The enzyme was purified from intercellular fluidof tomato leaves systemically in fected with TMV by -20℃ acetoneprecipitation and ion exchange chromatography on CM-Sephadex C-25, onDEAE-Sephadex A-25 and on Sephadex G-150, successively to homogeneity. Itsmolecular weight was determined by SDS PAGE, it was identified as aglycoprotein. The enzyme activity had an optimal pH of 4.0~4.4 and an optimaltemperature between 50~55℃, it was stable between pH 3.4~6.4. The K_(m) ofthe enzyme was 0.71 mmol/L and V_(max) was 6.1 #mu#mol mg~(-1) proteinmin~(-1). It was one of the predominant proteins in the intercellularfluid of tomato leaves systemically infected by TMV.

Key words: Tomato;apoplast protein;#beta#-palactosidase;Tobacco mosaic virus

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引用本文：

史益敏, 颜季琼, 费雪南, 许煜泉. 番茄叶片胞外β-半乳糖苷酶的纯化和性质[J]. 生理学报 1994; 46 (2): .

Shi Yimin, Yan Jiqiong, Fei Xuenan, Xu Yuquan. Purification and properties of #beta#-galactosidase from intercellular fluidof tomato leaves. Acta Physiol Sin 1994; 46 (2): (in Chinese with English abstract).