Multiple steroid-binding orientations: alteration of regiospecificity
نویسندگان
چکیده
The mutation of Ala-i 17 to Val conferred dehydroepiandrosterone (DHEA) hydroxylase activity on cytochrome P-450 2a-4, with the production of both 2aand 7ahydroxyDHEA at similar rates. P-450 2a-5 which has Val at position 117, acquired high DHEA hydroxylase activity by mutation of Phe-209. Mutant F209L of P-450 2a-5 exhibited strong regiospecificity at the 2-position of the DHEA molecule with the production of 2a-hydroxy DHEA as the major metabolite. On the other hand, mutant F209V of P-450 2a-5 showed the 7-position to be the major hydroxylation site, 7/3hydroxyDHEA and 7cx-OHDHEA being produced. Therefore the regiospecificity of DHEA hydroxylase activity of P-450 2a-5
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