Phillips I R, Shephard E A, Ashworth A, Rabin B R
Proc Natl Acad Sci U S A. 1985 Feb;82(4):983-7. doi: 10.1073/pnas.82.4.983.
A previously reported cDNA clone [pP450(1)] coding for a phenobarbital-inducible cytochrome P-450 variant of rat liver microsomal membranes, designated P-450e(U.C.), was used as a specific hybridization probe to screen a human liver cDNA library. Restriction mapping showed that two of the colonies isolated contained plasmids coding for overlapping regions of the same cDNA sequence. The clone [pHP450(1)] having the longer cDNA insert (1.25 kilobase pairs) was sequenced. The homology between the rat and human cDNAs is 62% in their coding regions but is only random (24%) in the 3'-noncoding nucleotides. The amino acid sequence deduced from the human cDNA is 50% identical to that of P-450e(U.C.). The homology increases to 72% if conservative changes in amino acid residues are permitted. The hydropathy profile of the polypeptide encoded by pHP450(1) is almost identical to that of P-450e(U.C.). Regions known to be highly conserved in cytochrome P-450 isozymes isolated from rat, rabbit, and mouse were found to be conserved in the amino acid sequence derived from pHP450(1). Analysis by Southern blotting indicated that the human cytochrome P-450 encoded by pHP450(1) is part of a multigene family.
一个先前报道的编码大鼠肝微粒体膜中苯巴比妥诱导型细胞色素P - 450变体（命名为P - 450e(U.C.)）的cDNA克隆[pP450(1)]，被用作特异性杂交探针来筛选人肝cDNA文库。限制性图谱分析表明，分离得到的两个菌落含有编码同一cDNA序列重叠区域的质粒。对具有较长cDNA插入片段（1.25千碱基对）的克隆[pHP450(1)]进行了测序。大鼠和人cDNA的编码区同源性为62%，但在3' - 非编码核苷酸中仅为随机同源（24%）。从人cDNA推导的氨基酸序列与P - 450e(U.C.)的氨基酸序列有50%相同。如果允许氨基酸残基发生保守性变化，同源性则增加到72%。由pHP450(1)编码的多肽的亲水性图谱与P - 450e(U.C.)的几乎相同。在从大鼠、兔子和小鼠中分离出的细胞色素P - 450同工酶中已知高度保守的区域，在源自pHP450(1)的氨基酸序列中也被发现是保守的。Southern印迹分析表明，由pHP450(1)编码的人细胞色素P - 450是一个多基因家族的一部分。
