Induction of β-oxidation enzymes and microbody proliferation in Aspergillus nidulans
Induction of β-oxidation enzymes and microbody proliferation in Aspergillus nidulans
复制标题
构巢曲霉中β-氧化酶的诱导和微体增殖
DOI：
10.1007/s002030050392
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发表时间：
1996
影响因子：
2.8
通讯作者：
F. Laborda
中科院分区：
文献类型：
--
作者：
S. Valenciano;J. R. Lucas;A. Pedregosa;I. F. Monistrol;F. Laborda
尼杜拉曲霉能够以油酸为唯一碳源生长。对油酸诱导的β氧化途径的表征表明，参与该分解代谢系统第一步的两种酶的活性是：酰辅酶A氧化酶和酰辅酶A脱氢酶。在线性蔗糖梯度中等压离心后，含有β-氧化酶、异柠檬酸裂解酶和过氧化氢酶的微体(过氧化物体)从含有延胡索酸酶的线粒体组分中被清楚地分离出来。在油酸上生长与许多微体的发育有关，这些微体散布在细胞质中。这些微体(过氧化物体)呈圆形至细长状，占细胞质体积的6%，以过氧化氢酶存在为特征。β氧化途径在醋酸盐培养的细胞中也被诱导，尽管水平较低；这些细胞缺乏酰基辅酶A氧化酶活性。然而，在醋酸盐上的生长并没有导致海藻微体的大规模增殖。
Aspergillus nidulans is able to grow on oleic acid as sole carbon source. Characterization of the oleate-induced β-oxidation pathway showed the presence of the two enzyme activities involved in the first step of this catabolic system: acyl-CoA oxidase and acyl-CoA dehydrogenase. After isopicnic centrifugation in a linear sucrose gradient, microbodies (peroxisomes) housing the β-oxidation enzymes, isocitrate lyase and catalase were clearly resolved from the mitochondrial fraction, which contained fumarase. Growth on oleic acid was associated with the development of many microbodies that were scattered throughout the cytoplasm of the cells. These microbodies (peroxisomes) were round to elongated, made up 6% of the cytoplasmic volume, and were characterized by the presence of catalase. The β-oxidation pathway was also induced in acetate-grown cells, although at lower levels; these cells lacked acyl-CoA oxidase activity. Nevertheless, growth on acetate did not cause a massive proliferation of microbodies in A. nidulans.