A NOVEL ROLE FOR LIGHT IN THE ACTIVATION OF RIBULOSEBISPHOSPHATE CARBOXYLASE OXYGENASE
A NOVEL ROLE FOR LIGHT IN THE ACTIVATION OF RIBULOSEBISPHOSPHATE CARBOXYLASE OXYGENASE
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DOI：
10.1104/pp.92.1.110
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发表时间：
1990-01-01
期刊：
影响因子：
7.4
通讯作者：
OGREN, WL
中科院分区：
文献类型：
--
作者：
CAMPBELL, WJ;OGREN, WL
在饱和浓度的 ATP 存在下，光刺激缓冲裂解叶绿体系统中核酮糖二磷酸羧化酶/加氧酶 (rubisco) 的活化。这表明除了先前确定的 ATP 合成要求之外，光在 rubisco 激活酶激活系统中也发挥着作用。 Rubisco 激活在低辐照度（每平方米每秒 10 微摩尔光子）下几乎与高辐照度（每平方米每秒 1000 微摩尔光子）一样大。 Light stimulation of activation occurred at both bicarbonate (equivalent to air levels of CO2) and high bicarbonate (10 mM) concentrations. Light activation was inhibited by DCMU and glyoxylate.甲基紫精不抑制光激活，二硫苏糖醇不刺激黑暗中的激活，表明铁氧还蛋白/硫氧还蛋白系统不参与其中。 Following a transition of the lysed chloroplasts from light to dark, the light-dependent increase in activation ceased immediately.实验使用菠菜 (Spinacea oleracea L.) 的叶绿体进行，菠菜此前已被证明不含有内源性 Rubisco 抑制剂 2-羧基阿滨醇 1-磷酸。 Assays of total rubisco activity in the light and dark confirmed the absence of such a tight binding inhibitor of activity.这里报道的观察结果不能用目前光在 Rubisco 激活中的作用的假设来解释，并且证明除了提供 Rubisco 激活酶活性所需的 ATP 之外，体内 Rubisco 的激活状态还需要至少一种其他光依赖性再激活。
Light stimulated the activation of ribulosebisphosphate carboxylase/oxygenase (rubisco) in a buffered lysed chloroplast system in the presence of saturating concentrations of ATP. This indicates a role for light in the rubisco activase activation system in addition to the previously identified requirement for the synthesis of ATP. Rubisco activation was nearly as great at low irradiance (10 micromoles of photons per square meter per second) as at high irradiance (1000 micromoles of photons per square meter per second). Light stimulation of activation occurred at both bicarbonate (equivalent to air levels of CO2) and high bicarbonate (10 mM) concentrations. Light activation was inhibited by DCMU and glyoxylate. Methyl viologen did not inhibit light activation, and dithiothreitol did not stimulate activation in the dark, indicating that the ferredoxin/thioredoxin system was not involved. Following a transition of the lysed chloroplasts from light to dark, the light-dependent increase in activation ceased immediately. The experiments were conducted with chloroplasts from spinach (Spinacea oleracea L.), a species which was previously shown not to contain the endogenous inhibitor of rubisco, 2-carboxyarbinitol 1-phosphate. Assays of total rubisco activity in the light and dark confirmed the absence of such a tight binding inhibitor of activity. The observations reported here cannot be explained by current hypotheses of the role of light in rubisco activation and demonstrate that in addition to providing ATP needed for rubisco activase activity, at least one other light-dependent reactivation is required the activation state of rubisco in vivo.