An improved equation and assay for determining the CO2/O-2 specificity for Rubisco

作者：Li GF; Mao HB; Ruan X; Xu Q; Gong YD; Zhang XF; Zhao NM^*

来源：Photosynthesis Research, 2003, 75(3): 287-292.

DOI：10.1023/A:1023957900429

• caculation error
• kinetics
• Rubisco
• RuBP
• specificity factor

The determination of the CO2/O-2 specificity factor (Omega) is very important to investigate the Rubisco carbon assimilation efficiency. In this paper, it is proved that previous formulae can introduce notable errors into calculating the CO2/O-2 specificity factor (Omega) because CO2 and O-2 are both the substrates and the mutually competitive inhibitors for Rubisco. A simple integrated equation is proposed to calculate the CO2/O-2 specificity factor (Omega). On the other hand, previous multi-step procedures, including the manipulation of radioisotope (C-14 and/or H-3) and the chromatographic separation of the products, are inconvenient and may cause much random error. An improved assay procedure is presented therefore, which includes the spectrophotometric measurement of 3-phosphoglycerate-dependent NADH oxidation with a coupled enzyme system.

• 出版日期2003
• 单位清华大学