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高等植物Rubisco的组装及其中间产物的鉴定

陈根云, 肖元珍, 李立人

中科院上海植物生理研究所.上海 200032

摘要

将新鲜制备的不含Rubisco的水稻叶片低分子量蛋白组分在离体条件下于室温保温48h,ND-PAGE分析发现在ATP 5mmol/L和Mg~(2+) 5mmol/L的作用条件下,在分子量为560kD位置上有一蛋白带生成。Western blot和SDS-PAGE分析证实在ATP和Mg~(2+)存在的情况下,组装成的蛋白确实是Rubisco全酶;而600kD的蛋白是由Rubisco大小亚基和cpn60的#alpha#、#beta#亚基组成的一个复合物,用~(35)S-Met同位素标记的水稻Rubisco小亚基前体通过跨膜运输与豌豆叶绿体中的大亚基进行异源重组后,发现除了组装成的异源Rubisco杂合酶外,还发现存在有多种组装中间体。根据这些中间体分子量的测定,推测了高等植物Rubisco在cpn60和cpn10作用下完成组装的可能途径。

关键词： RubisCO; 组装; 中间体; cpn60; cpn10

Rubisco assembly in higher plant and characterization of its intermediates

Chen Genyun, Xiao Yuanzhen, Li Liren

Shanghai Institute of Plant Physiology,Chinese Academy of Sciences.Shanghai 200032

Abstract

The results of Western blot and SDS-PAGE indicated that the HMW protein complex consisted of two kinds of ch-cpn60 (#alpha#&#beta#) subunits, the large subunit (LS) and small subunit (SS) of Rubisco, and some unknown proteins subunits. When the rice prSS labeled with ~(35)C-Met was incubated under light with intact chloroplasts from pea, and the supernatant of broken chloroplasts was analyzed by ND-PAGE and autoradiography, several radioactive protein bands appeared in the photo besides the assembled hybrid Rubisco. Their molecular weights varied from 70 to 600 kD. Some of their intermediates have been confirmed to contain LS and SS by Western blot analysis against anti-rice-LS serum. According to the molecular weights of the intermediates found, we proposed a pathway of Rubisco assembly in higher plant.

Key words: RubisCO;Assembly;Intermediates;cpn10;cpn60

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引用本文：

陈根云, 肖元珍, 李立人. 高等植物Rubisco的组装及其中间产物的鉴定[J]. 生理学报 2000; 52 (1): .

Chen Genyun, Xiao Yuanzhen, Li Liren. Rubisco assembly in higher plant and characterization of its intermediates. Acta Physiol Sin 2000; 52 (1): (in Chinese with English abstract).