Physiological role of D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein.
Physiological role of D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein.
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D-3-羟酰基-CoA 脱水酶/D-3-羟酰基-CoA 脱氢酶双功能蛋白的生理作用。
DOI：
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
T. Hashimoto
中科院分区：
文献类型：
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作者：
Ling;T. Kurosawa;M. Sato;Yasuyuki Suzuki;T. Hashimoto
过氧化体β-氧化螺旋的第二和第三反应被认为是由Enoyl-CoA水合酶/L-3-羟酰基-CoA脱氢酶双功能蛋白(L-双功能蛋白)催化的。最近，我们在哺乳动物的过氧化体中发现了D-3-羟基酰辅酶A脱水酶/D-3-羟基酰辅酶A脱氢酶双功能蛋白(D-双功能蛋白)。因此，我们研究了D-双功能蛋白的生理作用。在培养的人皮肤成纤维细胞中，L双功能蛋白和D-双功能蛋白的含量分别约为0.01和0.5微克/毫克蛋白。D-双功能蛋白将十六碳烯基-辅酶A转化为3-酮基-辅酶A的活性约为0.5mU/mg成纤维细胞蛋白。这一数值大约是成纤维细胞中L双功能蛋白的100倍。从双功能蛋白的活性与棕榈酸酯氧化速率、酰基辅酶A氧化酶和3-酮酰辅酶A硫解酶活性的比较来看，D-双功能蛋白在成纤维细胞中棕榈酸酯的过氧化体氧化中起主要作用。肝脏中L和D-双功能蛋白的含量约为2.5微克/毫克蛋白。因此，D-双功能蛋白在人体肝脏过氧化体脂肪酸氧化中也起着重要作用。考察了双功能蛋白对其他酰基辅酶A衍生物的烯醇基形式的作用。D-双功能蛋白与2-甲基十六烯酰辅酶A和3alpha，7alpha，12alpha-trihydroxy-5beta-cholest-2-4-烯-辅酶A反应，而不与L-双功能蛋白反应。我们认为，在过氧化体特异性氧化的不同类型的羧酸盐的反应中，2-甲基支链脂肪酸的氧化和胆固醇侧链缩短形成胆汁酸的反应是由D-双功能蛋白催化的，而不是L-双功能蛋白催化的。
The second and third reactions of the peroxisomal beta-oxidation spiral are thought to be catalyzed by enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (L-bifunctional protein). Recently, we found the presence of D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (D-bifunctional protein) in mammalian peroxisomes. Therefore, we studied the physiological role of the D-bifunctional protein. The contents of the L- and D-bifunctional proteins were about 0.01 and 0.5 microg/mg protein, respectively, in cultured human skin fibroblasts. The activity of conversion of hexadecenoyl-CoA to 3-ketopalmitoyl-CoA by the D-bifunctional protein was estimated to be about 0.5 milliunit/mg of fibroblast protein. This value was about 100-fold that of the L-bifunctional protein in the fibroblasts. From comparison of the activities of the bifunctional proteins with the rate of palmitate oxidation and the activities of acyl-CoA oxidase and 3-ketoacyl-CoA thiolase, it is proposed that the D-bifunctional protein plays a major role in the peroxisomal oxidation of palmitate in the fibroblasts. The contents of both the L- and D-bifunctional proteins in liver were about 2.5 microg/mg protein. Therefore, it is suggested that the D-bifunctional protein also plays a significant role in human liver peroxisomal fatty acid oxidation. Actions of the bifunctional proteins on enoyl forms of other acyl-CoA derivatives were examined. The D-bifunctional protein but not the L-bifunctional protein reacted with 2-methylhexadecenoyl-CoA and 3alpha,7alpha,12alpha-trihydroxy-5beta-cholest-2 4-enoyl-CoA. We propose that, among the reactions of the distinct group of carboxylates oxidized specifically in peroxisomes, oxidation of 2-methyl-branched fatty acids and side-chain shortening of cholesterol for bile acid formation are catalyzed by the D-bifunctional protein, but not the L-bifunctional protein.
来自大鼠肝脏过氧化物酶体的 D-3-羟酰辅酶 A 脱水酶。
DOI：
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发表时间：
1990
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Li,JX;Smeland,TE;Schulz,H
通讯作者：
Schulz,H
从大鼠肝微粒体中纯化的 β-羟酰基-CoA 脱水酶具有过氧化物酶体来源的证据。
DOI：
10.1042/bj2870091
发表时间：
1992
期刊：
The Biochemical journal
影响因子：
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作者：
Cook,L;Nagi,MN;Suneja,SK;Hand,AR;Cinti,DL
通讯作者：
Cinti,DL