STRUCTURE AND REGULATION OF CYTOCHROMES P-450

类固醇生成细胞色素P-450的研究将是 继续进一步描述了 六种类固醇生成细胞色素P-450（芳香化酶，11B- 羟化酶，C27侧链裂解，21-羟化酶，17 a- 羟化酶和C21侧链裂解）。 表征将 通过使用溴乙酰氧基- 类固醇，特别是结合到这些活性位点， 内切酶 这些酶目前正在经受 微测序和基因克隆相结合的方法; 这些程序将继续进行， 这些猪酶的测定;这一信息是至关重要的 对活性位点标记的解释。 组织 类固醇生成蛋白（P-450、P-450还原酶、细胞色素b5） 在猪和大鼠的睾丸和肾上腺微粒体中， 研究了去乙酰化烯醇酮结合蛋白的特性， 将细胞色素P-450与相邻的微粒体蛋白质连接， 用免疫电子技术确定这些蛋白质的排列 显微镜 这些微粒体蛋白的研究将利用 与上述抗体交叉反应的良好表征的抗体 来自猪和大鼠微粒体的蛋白质。

Investigation of steroidogenic cytochromes P-450 will be continued with further characterization of the active sties of the six steroidogenic cytochromes P-450 (aromatase, 11B- hydroxylase, C27 side-chain cleavage, 21-hydroxylase, 17a- hydroxylase and C21 side-chain cleavage). Characterization will be achieved by active site-affinity-labelling using bromoacetoxy- steroids that bind specifically to the active sites of these enzymes. The enzymes are presently being subjected to the combined approaches of microsequencing and genetic cloning; these procedures will be continued until the complete sequences of these porcine enzymes are determined; this information is vital to interpretation of active site labelling. The organization of steroidogenic proteins (P-450, P-450 reductase, cytochrome b5) within testicular and adrenal microsomes from pig and rat will be studied to characterize a pregnenolone-binding protein, to cross- link cytochromes P-450 to adjacent microsomal proteins and to determine the arrangement of these proteins by immunoelectron microscopy. These studies of microsomal proteins will make use of well characterized antibodies that cross-react with the above proteins from pig and rat microsomes.