Rothamsted Experimental Station, AL5 2JQ, Harpenden, Herts, UK.
Photosynth Res. 1987 Jan;11(2):97-108. doi: 10.1007/BF00018268.
In light and in darkness, exposure of leaf segments to CO2-free atmospheres caused a marked reduction in extractable RuBP carboxylase activity. By contrast, darkness caused a relatively small decrease in carboxylase activity in extracts from leaf segments kept in air containing CO2. Recovery of carboxylase activity in leaves during illumination in air after exposure to CO2-free conditions paralleled recovery of capacity for photosynthesis; in darkness recovery of carboxylase activity in leaves was slower than in the light. Extracts from leaves exposed to CO2-free conditions recovered activity when provided with CO2 and Mg(2+); there were clearly, however, substances in the extracts that modified the activity achieved and caused anomalous decreases and increases with time after extraction. Studies of the effect of orthophosphate on the activity of purified wheat carboxylase in vitro were consistent with the view that many of the effects observed on the activity of crude leaf extracts were due to orthophosphate content.
在光照和黑暗条件下，将叶片暴露于无二氧化碳的大气中会导致可提取的 RuBP 羧化酶活性明显降低。相比之下，叶片在含有二氧化碳的空气中保持时，黑暗只会导致羧化酶活性相对较小的下降。叶片在暴露于无二氧化碳条件后，在空气中进行光照时，羧化酶活性的恢复与光合作用能力的恢复平行；而在黑暗中，叶片中羧化酶活性的恢复比在光照中要慢。将叶片暴露于无二氧化碳条件下，当提供二氧化碳和 Mg(2+)时，提取物会恢复活性；然而，提取物中显然有一些物质会改变所达到的活性，并导致在提取后随着时间的推移出现异常的减少和增加。体外研究正磷酸盐对纯化小麦羧化酶活性的影响，与以下观点一致，即对粗叶片提取物活性的许多观察结果归因于正磷酸盐含量。
