Nabi N, Kominami S, Takemori S, Omura T
J Biochem. 1983 Nov;94(5):1517-27.
Rabbit antibodies against cytochrome P-450 (SCC), P-450 (11 beta), and P-450 (C-21) from bovine adrenal cortex were prepared, and it was confirmed that these three cytochrome P-450 species are immunologically distinct from one another. Cytoplasmic sites of synthesis of P-450 (SCC), P-450 (11 beta), and P-450 (C-21) in bovine adrenal cortex were determined by examining the presence of their nascent peptides on isolated free and bound ribosomes. Nascent peptides were released in vitro from ribosomes by [3H]puromycin in a high salt buffer in the presence of a detergent, and the nascent peptides of P-450 (SCC), P-450 (11 beta), and P-450 (C-21) were isolated by immunoprecipitation. The nascent peptides of these three cytochrome P-450 species were found in both free and bound ribosomal fractions, suggesting that they share common sites of synthesis in the cytoplasm. However, the nascent peptides of mitochondrial P-450 (SCC) and P-450 (11 beta) were more concentrated in the free ribosomal fraction, whereas those of microsomal P-450 (C-21) were more abundant in the bound ribosomal fraction. The nascent peptides of the three cytochrome P-450 species were released from the membrane-bound ribosomes of rough microsomes into the cytoplasmic surface of microsomal vesicles by puromycin treatment.
制备了针对牛肾上腺皮质细胞色素P - 450（SCC）、P - 450（11β）和P - 450（C - 21）的兔抗体，并证实这三种细胞色素P - 450在免疫学上彼此不同。通过检测新生肽在分离的游离核糖体和结合核糖体上的存在情况，确定了牛肾上腺皮质中P - 450（SCC）、P - 450（11β）和P - 450（C - 21）的细胞质合成位点。在去污剂存在的情况下，新生肽在高盐缓冲液中通过[3H]嘌呤霉素从核糖体中体外释放出来，然后通过免疫沉淀分离出P - 450（SCC）、P - 450（11β）和P - 450（C - 21）的新生肽。发现这三种细胞色素P - 450的新生肽存在于游离核糖体和结合核糖体部分，这表明它们在细胞质中有共同的合成位点。然而，线粒体P - 450（SCC）和P - 450（11β）的新生肽在游离核糖体部分更为集中，而微粒体P - 450（C - 21）的新生肽在结合核糖体部分更为丰富。通过嘌呤霉素处理，这三种细胞色素P - 450的新生肽从粗糙微粒体的膜结合核糖体释放到微粒体小泡的细胞质表面。
