Oxidation of heme c derivatives by purified heme oxygenase. Evidence for the presence of one molecular species of heme oxygenase in the rat liver.
Oxidation of heme c derivatives by purified heme oxygenase. Evidence for the presence of one molecular species of heme oxygenase in the rat liver.
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DOI：
10.1016/s0021-9258(18)33968-1
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发表时间：
1982-09
期刊：
影响因子：
--
通讯作者：
R. K. Kutty;M. Maines
中科院分区：
文献类型：
--
作者：
R. K. Kutty;M. Maines
在大鼠肝脏中只检测到一种血红素加氧酶分子。该酶催化原血红素（B型血红素蛋白的辅基部分）以及血红素C衍生物（血红素、血红素二甲酯、双半胱氨酰血红素和细胞色素C的血红素十一肽）的氧化。完整的细胞色素c不被氧化的酶。在血红素加氧酶、NADPH-细胞色素c（P-450）还原酶、NADPH和O_2的重组体系中，血红素和血红素十肽的氧化速率比血红素高2倍，而二半胱氨酰和二甲基血红素与血红素的氧化速率相当。研究了血红素加氧酶对血红素的氧化作用。“血胆绿素”的高效液相色谱图显示形成一个主要异构体（54%）和三个次要组分（20，17和9%）。只有血胆绿素的主要异构体被纯化的胆绿素还原酶还原为“血胆红素”。相反，二甲基血红素的氧化导致胆绿素的1个异构体的形成。细胞色素c的二甲基血红素、二半胱氨酰血红素和血红素十一肽的氧化产物不是胆绿素还原酶的底物，也没有产生可分离和表征的胆红素型化合物。血红素生成胆红素对血红素加氧酶有绝对的要求，
Only one molecular species of heme oxygenase was detected in the rat liver.“he enzyme catalyzed the oxidation of protoheme, the prosthetic moiety of b-type hemoproteins, as well as heme c derivatives: hematoheme, hematoheme dimethyl ester, dicysteinyl hematoheme, and heme undecapeptide of cytochrome c. Intact cytochrome c was not oxidized by the enzyme. In a reconstituted system of heme oxygenase, NADPH-cytochrome c (P-450) reductase, NADPH, and O,, the oxidation rates of hematoheme and heme uadecapeptide exceeded that of protoheme by 2-fold; md those of dicysteinyl and dimethyl hematoheme aad protoheme were comparable. The oxidation of hematoheme by heme oxygenase was investigated in detail. The high performance liquid chromatography pattern of “hematobiliverdin” revealed the formation of one major isomer (54%) and three minor components (20, 17, and 9%). Only the major isomer of hematobiliverdin was reduced to “hematobilirubin” by purified biliverdin reductase. In contrast, the oxidation of dimethyl hematoheme resulted in the formation of 1 isomer of biliverdin. The oxidation products of dimethyl hematoheme, dicysteinyl hematoheme, and heme undecapeptide of cytochrome c were not substrates for biliverdin reductase and did not yield bilirubin-type com-pounds which could be separated and characterized. The formation of hematobilirubin from hematoheme had an absolute requirement for heme oxygenase,