摘要
经硫酸铵分部沉淀、SephacrylS-300和DEAE-纤维素柱层析纯化了小球藻RubisCO,得率为15%,比活力达1.232μmolCO2ms-1min-1,分子量是500kD,它和菠菜叶片RubisCO在分子量、亚基组成和免疫特性等方面相似,反映RubisCO在高等和低等植物中有较高的同源性。自养小球藻RubisCO占细胞可溶性蛋白质的24%。而异养转变后的小球藻细胞内不含RubisCO。异养小球藻向自养生长转变过程中,20h后细胞内叶绿素含量逐渐增加,24h时细胞内出现RubisCO,24h后大量增加,至41h时含量达最高峰;标志着小球藻细胞光合作用能力的恢复和加强。
The RubisCO (E. C. 4. 1. 1. 39)from Chlorella protothecoides was purified(Table 1 and Fig. 3) by ammoniumsulfate fractionation and column chromatography on Sephacryl S-300 (Fig.1) and DEAE-cellulose (Fig. 2). The recovery was 15 %. The specific activity of the enzyme was 1. 232 μmol CO2 mg-1 protein min-1. Its molecular weight was 500 kD. The molecular weight, subunit constitution (Fig. 4)and immunoreactivity (Fig. 5) of the enzyme were similar to those from spinach leaves.The content of RubisCO in totalsoluble protein in autotrophic C. protothecoides cells was 24%. No RubisCO was found in heterotrophic C. protothecoides cells (Table 2 ). RubisCO appeared in the C. protothecoides cells 24 hafter transition from heterotrophy to autotrophy. Then it kept increasing until 41 h. Chlorophyll appeared 20 h after transition from heterotrophy to autotrophy(Fig. 6, 7).
基金
国家自然科学基金
植物分子遗传国家重点实验室基金
关键词
小球藻
自养
二磷酸核酮糖
羧化酶
加氧酶
提纯
Chlorella protothecoides , RubisCO, purification, homologous properties , autotrophy, heterotrophy