Effect of detergents on the N-and ring-hydroxylation of 2-acetamidofluorene by hamster liver microsomal preparations.

Effects of detergents such as cholate, deoxycholate and Triton X-100 were studied on N-and ring-hydroxylation of 2-acetamidofluorene by reconstituted and unresolved microsomal systems from livers of hamsters pretreated with 3-methylcholanthrene. Triton X-100 (2.5 mg/nmol of cytochrome P-448) inhibited N-and ring-hydroxylation by wholemicrosomal preparations by 40 and 90% respectively Deoxycholate at the same concentration inhibited both hydroxylations completely, whereas cholate inhibited N-and ring-hydroxylation by 40 and 50% respectively. In reconstitution studies, the presence of Triton X-100(0.5-1.0mg/nmol of cytochrome P-448) along with unsolubilized cytochrome P-448 fraction and solubilized reductase fraction increased N-hydroxylation to an appreciable extent compared with ring-hydroxylation. Both cholate and deoxycholate at 0.5-1.0 mg concentrations had a greater stimulatory effect on ring-than on N-hydroxylation activity in such a reconstituted system.