Inhibition of @entity24288 epoxidase by @entity4974 antimycotic compounds. A comparative study of the fungal and XXXX enzymes.

@entity1 @entity24288 @entity8974 @entity7409 @entity5132 @entity4974 @entity35 @entity375
The inhibition of @entity24288 epoxidase by the @entity4974 antimycotic agents naftifine and compound @entity8974 was investigated, with particulate enzyme preparations from the pathogenic @entity375 @entity5132 and @entity7409 and from @entity35 liver. Both naftifine and compound @entity8974 were potent inhibitors of the Candida epoxidases and showed apparently non-competitive kinetics with respect to the substrate @entity24288 . The Ki values for naftifine and compound @entity8974 in the @entity5132 system were 1.1 microM and 0.03 microM respectively. The @entity7409 enzyme was slightly more sensitive to inhibition. Varying the concentrations of cofactors or the soluble cytoplasmic fraction (S200) had no effect on the inhibition. The epoxidase from @entity35 liver was much less sensitive (Ki for compound @entity8974 was 77 microM). The inhibition was also qualitatively different from that in Candida, being competitive with respect to @entity24288 and also with respect to the S200 fraction. S200 fraction derived from @entity5132 also antagonized the inhibition of the epoxidase from liver, but the liver S200 fraction did not affect inhibition of the Candida enzyme by compound @entity8974 . There was no evidence for an irreversible or mechanism-based inhibition of either the fungal or the @entity1 epoxidase. The selective inhibition of @entity24288 epoxidase was sufficient to account for the known antimycotic action of the compounds.
