Evidence for cytochrome b5 as an electron donor in ricinoleic acid biosynthesis in microsomal preparations from developing castor bean (Ricinus communis L.).
Evidence for cytochrome b5 as an electron donor in ricinoleic acid biosynthesis in microsomal preparations from developing castor bean (Ricinus communis L.).
复制标题
细胞色素 b5 作为来自发育中的蓖麻子 (Ricinus communis L.) 的微粒体制剂中蓖麻油酸生物合成的电子供体的证据。
DOI：
10.1042/bj2870141
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
K. Stobart
中科院分区：
文献类型：
--
作者：
Mark A. Smith;Lisbeth Jonsson;S. STYMNEt;K. Stobart
蓖麻胚乳微粒体膜制备物中b型细胞色素主要为细胞色素b5。细胞色素P-450也存在。微粒体膜具有δ 12-羟化酶活性，并催化油酸的NAD(P) h依赖性羟化反应生成蓖麻油酸。CO对羟化酶活性无影响。从花菜小花微粒体中纯化亲水性细胞色素b5片段，制备兔多克隆抗体。抗（细胞色素b5） IgG可抑制12-羟化酶、12-去饱和酶和细胞色素c还原酶的活性。结果表明，NAD(P)H的电子通过细胞色素b5转移到羟基化位点，细胞色素P-450没有参与。
The major b-type cytochrome in microsomal membrane preparations from developing endosperm of castor bean (Ricinus communis) was cytochrome b5. Cytochrome P-450 was also present. The microsomal membranes had delta 12-hydroxylase activity and catalysed the NAD(P)H-dependent hydroxylation of oleate to yield ricinoleic acid. CO had no effect on the hydroxylase activity. Rabbit polyclonal antibodies were raised against the hydrophilic cytochrome b5 fragment purified from cauliflower (Brassica oleracea) floret microsomes. The anti-(cytochrome b5) IgG inhibited delta 12-hydroxylase, delta 12-desaturase and cytochrome c reductase activity in the microsomes. The results indicate that electrons from NAD(P)H were transferred to the site of hydroxylation via cytochrome b5 and that cytochrome P-450 was not involved.