Molecular cloning, heterologous expression, and characterization of a novel member of CYP2A in the Syrian hamster

The cDNA clone coding for a novel cytochrome P-450 2A subfamily member (CYP 2A16) was isolated from a Syrian hamster liver cDNA library. The deduced am ino acid sequence of CYP2A16 showed more than 90% identity with those of ra t CYP2A3 and mouse CYP2A4/5. The catalytic activity bf CYP2A16 was determin ed by transient expression of its cDNA in transfected COS7 cells and CYP2A1 6 was found to have the testosterone 2 beta-, 15 alpha-, and 15 beta-hydrox ylases, coumarin 7-hydroxylase, and ethoxycoumarin O-deethylase activities. These enzymatic characteristics of CYP2A16 are different from those of oth er Syrian hamster CYP2A subfamily members, CYP2A8 and CYP2A9. Northern blot analysis showed that CYP2A16 was expressed in kidney and lung while most o f the other CYP2A subfamily members have been reported to be expressed in l iver and olfactory. These observations indicated that the Syrian hamster CY P3A16 had unique properties compared with those of other CYP2A subfamily me mbers. (C) 1999 Elsevier Science B.V. All rights reserved.