PARTICULATE AND SOLUBLE LIPOXYGENASE ISOENZYMES - COMPARISON OF MOLECULAR AND ENZYMATIC-PROPERTIES
PARTICULATE AND SOLUBLE LIPOXYGENASE ISOENZYMES - COMPARISON OF MOLECULAR AND ENZYMATIC-PROPERTIES
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DOI：
10.1007/bf00201030
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发表时间：
1994-06-01
期刊：
影响因子：
4.3
通讯作者：
KINDL, H
中科院分区：
文献类型：
--
作者：
FEUSSNER, I;KINDL, H
黄瓜(Cucumis sativus L.)子叶是一种研究代谢区划变化的植物模型系统，含有至少六种形式的脂氧合酶。研究了脂氧合酶在脂小体、微粒体和胞浆中的细胞内定位和细胞器拓扑结构。设计了一种溶解和制备具有酶活性的脂体脂肪氧合酶的方案。溶解脂体形式所需的方法不同于从微粒体膜上溶解两种脂氧合酶形式所适用的程序。提纯了三种胞质脂氧合酶，发现它们在大小和电荷上是可区分的。通过比较酶的性质，进一步鉴定和区分了所有细胞脂肪氧合酶亚型。颗粒结合型脂肪氧合酶的最适pH值有显著差异：脂体脂肪加氧酶的最适pH为8.5，微粒体脂加氧酶的最适pH为5.5。此外，对产物的分析表明，脂体脂肪氧合酶和微粒体脂氧合酶的催化性质彼此之间以及与可溶性脂氧合酶有明显的区别。
Cucumber (Cucumis sativus L.) cotyledons, a plant model system for studying changes in metabolic compartmentation, contain at least six forms of lipoxygenase. The intracellular location and organellar topology of lipoxygenase forms in lipid bodies, microsomes, and cytosol were investigated. A protocol was worked out to solubilize and prepare lipid-body lipoxygenase in an enzymatically active form. The methodology required for the solubilization of the lipid-body form differed from the procedure applicable for solubilization of two lipoxygenase forms from the microsomal membranes. Three cytosolic lipoxygenases were purified and found to be distinguishable from each other in size and charge. Further characterization and differentiation of all cellular lipoxygenase isoforms was achieved by comparison of the enzymatic properties. Marked differences in pH optima of the particle-bound lipoxygenases were found: optimal pH of 8.5 for lipid-body lipoxygenase and pH 5.5 for the microsomal lipoxygenases. In addition, analysis of the products formed showed that the catalytic properties of lipid-body lipoxygenase and microsomal lipoxygenase are clearly distinguishable from each other and from the soluble forms.