Primary structures of multiple forms of cytochrome P-450 isozyme 2 derived from rabbit pulmonary and hepatic cDNAs.
Primary structures of multiple forms of cytochrome P-450 isozyme 2 derived from rabbit pulmonary and hepatic cDNAs.
复制标题
源自兔肺和肝 cDNA 的多种形式的细胞色素 P-450 同工酶 2 的一级结构。
作者：
R. Gasser;M. Negishi;R. Philpot
利用兔肺和肝mRNA构建cDNA文库，用cDNA探针（pf 3/46）筛选与大鼠细胞色素P-450b同源的小鼠细胞色素P-450文库。利用bsteii进行限制性内切分析，鉴定出3种cDNA克隆。由肺mRNA构建的文库中存在两种类型的克隆（B0和B1）。B0 cDNA的核苷酸序列编码一种由491个氨基酸组成的蛋白质，其序列与同工酶2的序列相同。从b1 cDNA衍生的序列也包含491个氨基酸，但与B0序列有6个位置不同。用单次苯巴比妥处理12小时后，从肝脏mRNA构建文库中获得B1克隆。从该文库中还获得了第三种克隆（B2），但未发现B0克隆。该序列由B2 cDNA衍生而来，包含491个氨基酸，与B0和B1序列分别有11个和15个位置不同。第二个肝脏cDNA文库由每天服用苯巴比妥4天的家兔肝脏mRNA构建，包含B0个克隆。其中一个序列被发现与肺B0克隆的序列相同。
Rabbit pulmonary and hepatic mRNA was used to construct cDNA libraries that were screened with a cDNA probe (pf 3/46) to murine cytochrome P-450 homologous with rat cytochrome P-450b. Three types of cDNA clones were identified on the basis of restriction analysis with Bst EII. Two types of clones (B0 and B1) were present in a library constructed from pulmonary mRNA. The nucleotide sequence of B0 cDNA encodes a protein of 491 amino acids having a sequence identical to one reported for isozyme 2. The sequence derived from the b1 cDNA also contains 491 amino acids but differs from the B0 sequence at six positions. B1 clones were also obtained from a library constructed from hepatic mRNA isolated 12 hr after a single treatment with phenobarbital. A third type of clone (B2) was also obtained from this library, but no B0 clones were found. The sequence derived from the B2 cDNA contains 491 amino acids and differs from the B0 and B1 sequences at 11 and 15 positions, respectively. A second hepatic cDNA library, constructed from mRNA from the liver of a rabbit treated with phenobarbital daily for 4 days, contained B0 clones. The sequence of one of these was found to be identical to that of the pulmonary B0 clones.