Oxidations of various substrates and effects of the inhibitors on purified mitochondria isolated from Kalanchoë pinnata
Oxidations of various substrates and effects of the inhibitors on purified mitochondria isolated from Kalanchoë pinnata
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各种底物的氧化和抑制剂对从长寿花中分离的纯化线粒体的影响
DOI：
10.1007/s10535-005-1208-x
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发表时间：
2005
影响因子：
1.5
通讯作者：
S. Agarie
中科院分区：
文献类型：
--
作者：
H. T. K. Hồng;A. Nose;S. Agarie
长寿花线粒体很容易以高速率和耦合氧化琥珀酸、苹果酸、NADH 和 NADPH。通常在琥珀酸盐存在的情况下观察到最高的呼吸速率。在 pH 6.8 下，使用焦磷酸硫胺素观察到苹果酸氧化率很高，其中苹果酸酶 (ME) 和丙酮酸脱氢酶都被激活。在 K 的 CAM 第三阶段。羽状线粒体中，ME 和苹果酸脱氢酶（MDH）同时参与苹果酸的代谢。然而，ME发挥了主要作用：苹果酸通过ME氧化产生丙酮酸和CO2，而不是通过MDH氧化产生草乙酸(OAA)。两种或三种底物的协同氧化伴随着总呼吸速率的急剧增加。我们的结果表明，在 pH 6.8 下，替代 (Alt) 途径在辅酶 A 和 NAD+ 的苹果酸氧化中更加活跃，其中 ME 起作用并受到刺激，表明 ME 和 Alt 途径都与光期间的苹果酸脱羧有关。墨水。羽状线粒体、NADH 和 NADPH 氧化对 KCN 的氧化比对琥珀酸和苹果酸氧化更敏感，表明这些氧化与细胞色素途径而不是 Alt 途径有关，并且这些能力对于为细胞质丙酮酸正磷酸二激酶活性提供足够的能量是理想的。
Kalanchoë pinnatamitochondria readily oxidized succinate, malate, NADH, and NADPH at high rates and coupling. The highest respiration rates usually were observed in the presence of succinate. The high rate of malate oxidation was observed at pH 6.8 with thiamine pyrophosphate where both malic enzyme (ME) and pyruvate dehydrogenase were activated. In CAM phase III ofK. pinnatamitochondria, both ME and malate dehydrogenase (MDH) simultaneously contributed to metabolism of malate. However, ME played a main function: malate was oxidizedviaME to produce pyruvate and CO2rather thanviaMDH to produce oxalacetate (OAA). Cooperative oxidation of two or three substrates was accompanied with the dramatic increase in the total respiration rates. Our results showed that the alternative (Alt) pathway was more active in malate oxidation at pH 6.8 with CoA and NAD+where ME operated and was stimulated, indicating that both ME and Alt pathway were related to malate decarboxylation during the light. InK. pinnatamitochondria, NADH and NADPH oxidations were more sensitive with KCN than that with succinate and malate oxidations, suggesting that these oxidations were engaged to cytochrome pathway rather than to Alt pathway and these capacities would be desirable to supply enough energy for cytosol pyruvate orthophosphate dikinase activity.