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苹果果肉质膜微囊主动运输Ca~(2+)的Ca~(2+)-ATP酶特性

周卫, 何萍

中国农业科学院土壤肥料研究所.北京 100081

摘要

Ca~(2+)-ATP酶存在于苹果果肉质膜上并受载体A_(23187)刺激而活性增加,该酶活性与依赖于ATP的Ca~(2+)运输依抑制剂EB、游离Ca~(2+)和ATP浓度的变化并呈极为相似的饱和动力学特征;而其EB半抑制浓度,Ca~(2+)和ATP半饱和浓度分别为0.1、0.1和50#mu#mol/L,从而证实了正是Ca~(2+)-ATP酶推动苹果果肉质膜微囊的Ca~(2+)的主动运输。生长素与萘乙酸均可促进苹果果肉质膜微囊Ca~(2+)-ATP酶活性和Ca~(2+)吸收,而赤霉素则无此作用。

关键词： 质膜微囊; Ca~(2+)-ATP酶; Ca~(2+)主动运输; 激素; 苹果果肉

Characterization of Ca~(2+)-ATPase which drives active transport of Ca~(2+) in plasma membrane vesicles isolated from pulp cell of Malus pumila fruits

Zhou Wei, He Ping

Soil and Fertilizer Institute,Chinese Academy of Agricultural Sciences.Beijing 100081

Abstract

The relationship between Ca~(2+)-dependent ATPase(Ca~(2+)-ATPase) and ATP-dependent Ca~(2+) transport in plasma membrane vesicles isolated from pulp cell of Malus pumila fruits and the influence of hormones on this enzyme were investigated by using ~(45)Ca~(2+) tracing. Results showed that the Ca~(2+) ionophore A_(23187) and is localized at the plasma membrane. Ca~(2+)-ATPase activity and ATP-dependent Ca~(2+) uptake show very similar saturation kinetics with erythrosin B (50% inhibition at about 0.1 #mu#mol/L), free Ca~(2+) (half-maximal rate at about 0.1 #mu#mol/L), and ATP (K_(m) 50 #mu#mol/L), demonstrating that it is this enzyme that drives ATP-dependent Ca~(2+) transport in plasma membrane vesicles. Both Ca~(2+)-ATPase and Ca~(2+) uptake could be promoted also by IAA or NAA, but none by GA.

Key words: Plasma membrane vesicles;Ca~(2+)-ATPase;Ca~(2+) transport;Hormone;Pulp cell of Malus pumila fruits

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引用本文：

周卫, 何萍. 苹果果肉质膜微囊主动运输Ca~(2+)的Ca~(2+)-ATP酶特性[J]. 生理学报 1999; 51 (2): .

Zhou Wei, He Ping. Characterization of Ca~(2+)-ATPase which drives active transport of Ca~(2+) in plasma membrane vesicles isolated from pulp cell of Malus pumila fruits. Acta Physiol Sin 1999; 51 (2): (in Chinese with English abstract).