LACK OF ACONITASE IN GLYOXYSOMES AND PEROXISOMES
LACK OF ACONITASE IN GLYOXYSOMES AND PEROXISOMES
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DOI：
10.1042/bj2940103
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发表时间：
1993-08-15
影响因子：
4.1
通讯作者：
DOUCE, R
中科院分区：
文献类型：
--
作者：
COURTOISVERNIQUET, F;DOUCE, R
这项工作的目的是找出乌头酸酶[柠檬酸（异柠檬酸）水解酶，EC 4.2.1.3]，这是迅速失活的H2O2，是否存在于微体从植物细胞。完整的细胞器从蓖麻（Ricinus communis）胚乳和马铃薯（Solanum tuberosum）块茎的分离表明，顺乌头酸酶活性基本上是有限的线粒体和胞质溶胶部分，但没有检测到在高度纯化的蓖麻胚乳和马铃薯块茎过氧化物酶体。一个各向同性的电动势。在微体中未检测到氧化乌头酸酶的3Fe簇所预期的信号类型。在免疫印迹分析中，针对马铃薯块茎线粒体顺乌头酸酶产生的抗体不与任何乙二醛体或过氧化物酶体蛋白发生交叉反应。蓖麻胚乳细胞质组分和线粒体呈阳性反应。在分离的乙醛酸体中的完整乙醛酸循环的操作需要在孵育培养基中存在乌头酸酶。它的结论是，乙醛酸酶体可能是缺乏乌头酸酶和乙醛酸循环需要绕道通过胞质溶胶，其中包含一个强大的乌头酸酶活性。
The aim of this work was to find out whether aconitase [citrate (isocitrate) hydro-lyase, EC 4.2.1.3] which is rapidly inactivated by H2O2, is present in the microbodies from plant cells. The separation of intact organelles from castor-bean (Ricinus communis) endosperm and potato (Solanum tuberosum) tuber indicated that aconitase activity is essentially limited to the mitochondria and cytosol fraction, but was not detected in highly purified castor-bean endosperm and potato tuber peroxisomes. An isotropic e.p.r. signal of the type expected for the 3Fe cluster of oxidized aconitase was not detected in microbodies. In immunoblot analyses, antibodies raised against potato tuber mitochondrial aconitase did not cross-react with any glyoxysomal or peroxisomal protein. Positive reactions were found for cytosol fraction and mitochondria of castor-bean endosperm. The operation of the full glyoxylate cycle in isolated glyoxysomes requires the presence of aconitase in the incubation medium. It is concluded that glyoxysomes are probably devoid of aconitase and that the glyoxylate cycle requires a detour via the cytosol, which contains a powerful aconitase activity.