Cherrington N J, Falls J G, Rose R L, Clements K M, Philpot R M, Levi P E, Hodgson E
Department of Toxicology, North Carolina State Universitiy, Raleigh 27695, USA.
J Biochem Mol Toxicol. 1998;12(4):205-12. doi: 10.1002/(sici)1099-0461(1998)12:4<205::aid-jbt2>3.0.co;2-p.
Full-length cDNA clones encoding FMO1 and FMO5 have been isolated from a library constructed with mRNA from the liver of a female CD-1 mouse. The derived sequence of FMO1 contains 2310 bases: 1596 in the coding region, 301 in the 5'-flanking region, and 413 in the 3'-flanking region. The sequence for FMO5 consists of 3168 bases; 1599 in the coding region, 812 in the 5'-flanking region, and 757 in the 3'-flanking region. The sequence of FMO1 encodes a protein of 532 amino acids with a predicted molecular weight of 59.9 kDa and shows 83.3% identity to human FMO1 and 83-94% identity to other FMO1 homologs. FMO5 encodes a protein of 533 amino acids with a predicted molecular weight of 60.0 kDa and 84.1% identity to human FMO5 and 83-84% identity to other FMO5 orthologs. Two GxGxxG putative pyrophosphate binding domains exist beginning at positions 9 and 191 for FMO1, and 10 and 192 for FMO5. Mouse FMO1 and FMO5 were expressed in E. coli and show similar mobility to the native proteins as determined by SDS-PAGE. The expressed FMO1 protein showed activity toward methimazole, and FMO5 was active toward noctylamine. In addition, FMO1 was shown to metabolize radiolabeled phorate, whereas FMO5 showed no activity toward phorate.
已从用雌性CD-1小鼠肝脏mRNA构建的文库中分离出编码FMO1和FMO5的全长cDNA克隆。FMO1的推导序列包含2310个碱基：编码区1596个碱基，5'侧翼区301个碱基，3'侧翼区413个碱基。FMO5的序列由3168个碱基组成；编码区1599个碱基，5'侧翼区812个碱基，3'侧翼区757个碱基。FMO1的序列编码一个由532个氨基酸组成的蛋白质，预测分子量为59.9 kDa，与人类FMO1的同一性为83.3%，与其他FMO1同源物的同一性为83 - 94%。FMO5编码一个由533个氨基酸组成的蛋白质，预测分子量为60.0 kDa，与人类FMO5的同一性为84.1%，与其他FMO5直系同源物的同一性为83 - 84%。FMO1从第9位和第191位开始存在两个GxGxxG推定的焦磷酸结合结构域，FMO5从第10位和第192位开始存在。小鼠FMO1和FMO5在大肠杆菌中表达，通过SDS-PAGE测定，它们与天然蛋白质具有相似的迁移率。表达的FMO1蛋白对甲巯咪唑有活性，FMO5对辛胺有活性。此外，FMO1被证明能代谢放射性标记的甲拌磷，而FMO5对甲拌磷无活性。
