Department of Biochemistry, University of Nevada, Reno, Nevada 89557-0014.
Plant Physiol. 1991 May;96(1):208-13. doi: 10.1104/pp.96.1.208.
The level of 2-carboxyarabinitol 1-phosphate (CA1P) in leaves of 12 species was determined by an isotope dilution assay. (14)C-labeled standard was synthesized from [2-(14)C]carboxyarabinitol 1,5-bisphosphate using acid phosphatase, and was added at the initial point of leaf extraction. Leaf CA1P was purified and its specific activity determined. CA1P was found in dark-treated leaves of all species examined, including spinach (Spinacea oleracea), wheat (Triticum aestivum), Arabidopsis thaliana, and maize (Zea mays). The highest amounts were found in bean (Phaseolus vulgaris) and petunia (Petunia hybrida), which had 1.5 to 1.8 moles CA1P per mole ribulose 1,5-bisphosphate carboxylase catalytic sites. Most species had intermediate amounts of CA1P (0.2 to 0.8 mole CA1P per mole catalytic sites). Such intermediate to high levels of CA1P support the hypothesis that CA1P functions in many species as a light-dependent regulator of ribulose 1,5-bisphosphate carboxylase activity and whole leaf photosynthetic CO(2) assimilation. However, CA1P levels in spinach, wheat, and A. thaliana were particularly low (less than 0.09 mole CA1P per mole catalytic sites). In such species, CA1P does not likely have a significant role in regulating ribulose 1,5-bisphosphate carboxylase activity, but could have a different physiological role.
12 种植物叶片中的 2-羧基-D-阿拉伯糖醇 1-磷酸（CA1P）水平通过同位素稀释测定法确定。（14）C 标记的标准品是使用酸性磷酸酶从[2-（14）C]羧基-D-阿拉伯糖醇 1,5-双磷酸合成的，并在叶片提取的初始点加入。纯化了叶片 CA1P，并测定其比活性。在所有受光处理的叶片中均发现 CA1P，包括菠菜（Spinacea oleracea）、小麦（Triticum aestivum）、拟南芥（Arabidopsis thaliana）和玉米（Zea mays）。在豆类（Phaseolus vulgaris）和矮牵牛（Petunia hybrida）中发现的 CA1P 量最高，其每摩尔核酮糖 1,5-二磷酸羧化酶催化位点的 CA1P 含量为 1.5 至 1.8 摩尔。大多数物种具有中等含量的 CA1P（0.2 至 0.8 摩尔 CA1P 每摩尔催化位点）。CA1P 的这种中等至高水平支持 CA1P 在许多物种中作为光依赖性核酮糖 1,5-二磷酸羧化酶活性和整个叶片光合 CO2同化的调节剂的假说。然而，菠菜、小麦和拟南芥中的 CA1P 含量特别低（每个催化位点的 CA1P 少于 0.09 摩尔）。在这些物种中，CA1P 不太可能在调节核酮糖 1,5-二磷酸羧化酶活性方面发挥重要作用，但可能具有不同的生理作用。
