光照叶绿体对香豆酸的羟基化作用。超氧化物的作用。
Hydroxylation of p-Coumaric acid by illuminated chloroplasts. The role of superoxide.
作者信息
Halliwell B
出版信息
Eur J Biochem. 1975 Jul 1;55(2):355-60. doi: 10.1111/j.1432-1033.1975.tb02169.x.
Abstract
- Chloroplasts isolated from leaves of spinach-beet (Beta vulgaris L. ssp. vulgaris) do not catalyse the hydroxylation of p-coumaric acid in the dark unless a reductant (such as ascorbate, NADH or NADPH) is added. Superoxide dismutase has no effect on this reaction. 2. Illuminated chloroplasts catalyse the hydroxylation in the absence of added reductant. This reaction is completely inhibited by superoxide dismutase, but catalase has little effect. 3. Both hydroxylation in the light and hydroxylation in the dark in the presence of reductants are inhibited by diethyldithiocarbamate, EDTA, cyanide and 2-mercaptoethanol. 4. It is proposed that O-2- generated by illuminated chloroplasts is involved in the provision of a reductant to the enzyme phenolase.
摘要
- 从菠菜甜菜（甜菜 Beta vulgaris L. ssp. vulgaris）叶片中分离出的叶绿体，在黑暗中不会催化对香豆酸的羟基化反应，除非添加还原剂（如抗坏血酸、NADH 或 NADPH）。超氧化物歧化酶对该反应无影响。2. 光照下的叶绿体在不添加还原剂的情况下催化羟基化反应。此反应被超氧化物歧化酶完全抑制，但过氧化氢酶影响很小。3. 光照下的羟基化反应以及在有还原剂存在时黑暗中的羟基化反应均被二乙基二硫代氨基甲酸盐、EDTA、氰化物和 2 - 巯基乙醇抑制。4. 有人提出，光照下的叶绿体产生的 O₂⁻ 参与为酚酶提供还原剂的过程。
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