新月弯孢霉P450酶在甾体11β羟基化过程中的作用

Role of Curvularia lunata Cytochrome P450 During the 11β-Hydroxylation of Steriod

目的 :考察底物 17α 羟基孕甾 4 烯 3 ,2 0 二酮 2 1 醋酸酯 (RSA)对P450酶的诱导作用 ,探讨P450酶在细胞内作用的部位 ,进而研究P450酶与新月弯孢霉转化氢化可的松能力的关系。方法 :采用CO差光谱法对新月弯孢霉P450酶含量进行检测 ,分别在转化过程的不同时期加入不同浓度的RSA ,检测P450酶含量和氢化可的松产量。分别考察RSA在菌体细胞悬液和去菌体细胞上清液中的转化情况。结论 :RSA对P450酶具有诱导作用 ,在对数期初期 (12h)加入 0 5g/L的RSA对P450酶的诱导作用最佳 ,对细胞的生长抑制作用较小。P450酶是胞内酶。氢化可的松转化过程中 ,在对数生长期 ,P450酶含量平稳升高 ,进入产氢化可的松时期后 ,经过一段迟滞期 ,P450酶含量迅速增高。

AIM:The purpose is to study the induction of 17α -hydro xypregna-4-ene-3,20-dione-21-acetate(RSA) to cytochrome P450 and the exist ing posit ion of cytochrome P450 Meanwhile the relationship between cytochrome P450 and hydrocortisone yield was observed. METHOD:Reduced CO-differenc e spectrum method was used to study the cytochrome P450 activity of the protoplas t of Curvularia lunata. The P450 activity of the different age cells which were cultured in the different concentrations of RSA was observed. CONC LUSION: The results showed that the 0 5g/L RSA could induce the P450 act i vity obviously but not inhibit the growth of cells at the beginning of the expon ential phase of growth(12 h). Cytochrome P450 is intracellular enzyme. During the expo nential phase of growth, the cytochrome P450 activity increased smoothly. However during the phase producing hydrocortisone, the cytochrome P450 activity increas ed rapidly after a lag phase. The results showed that the hydrocortisone format ion rate was belonging to the cytochrome P450 activity.