Issue Archive

Purification of RubisCO from rice and its properties compared with those of tobacco

Miao Yougang, Li Liren

Shanghai Inst. Plant Physiol., Acad. Sin.

Abstract

The eluted samples were layered on a linear gradient of 25% to 40% (w/v) sucrose and centrifuged at 240000xg for 2.5 hours. The active fractions were pooled and applied to a column of DEAT-Sepharose fast flow, and eluted with the same buffer containing a linear gradient of 0 to 0.5 mmol/L NaCl. The specific activityof the purified enzyme was about 1.15 MUmol CO sub(2) mg super(-1) protein min super(-1). It was found that rice RubisCO was more labile to heat than the tobacco enzyme. Addition of Mg super(2+) had no effect on the tobacco enzyme. The total SH groups and the surface SH groups for rice and tobacco enzymes were the same However, the surface SH groups of the two enzymes after heat reactivation showed a significant difference. When all surface SH groups were modified by DTNB, the rice enzyme lost 60% of its activity, but the tobacco enzyme lost only 15%. These results indicate that the difference in properties between rice and tobacco enzymes were probably caused by the differences in their structure.

Key words: RubisCO;Rice;Tobacco;Purification

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Miao Yougang, Li Liren. Purification of RubisCO from rice and its properties compared with those of tobacco. Acta Physiol Sin 1991; 43 (2): (in Chinese with English abstract).