Cytochrome b5 involvement in cytochrome P450 monooxygenase activities in house fly microsomes

✍ Scribed by Minli Zhang; Dr. Jeffrey G. Scott

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 777 KB
• Volume: 27
• Category: Article
• ISSN: 0739-4462
• DOI: 10.1002/arch.940270306

✦ Synopsis

The involvement of cytochrome bs in different cytochrome P450 monooxygenase and palmitoyl CoA desaturase activities in microsomes from insecticide-resistant (LPR) house flies was determined using a specific polyclonal antiserum developed against house fly cytochrome bg. Anti-b5 antiserum inhibited the reduction of cytochrome b5 by NADHqtochrome bg reductase. The antiserum also inhibited palmitoyl CoA desaturase, rnethoxycoumarin-Odemethylase (MCOD), ethoxycoumarin-Odeethylase (ECOD), and benzo[a] pyrene hydroxylase (aromatic hydrocarbon hydroxylase, AHH) activities.

However, methoxyresorufin-Odemethylase (MROD) and ethoxyresorufin-Odeethylase (EROD) activities were not affected by this antiserum. These results demonstrate that cytochrome bs is involved in fatty acyl CoA desaturase activities and in certain cytochrome P450 monooxygenase activities (i.e., MCOD, ECOD, and AHH) in LPR house fly microsomes. Other cytochrome P450 monooxygenase activities (i.e., MROD and EROD) may not require cytochrome bg. The results suggest that cytochrome b5 involvement with cytochrome P450 monooxygenase activities is dependent upon the cytochrome P450 isoform involved. o 1994 ~i ~e y -~i s s , ~nc.