Enzyme inhibition by steroid anaesthetic agents derived from progesterone.

The anaesthetic potency of steroids related by metabolism to progesterone shows marked variation with small changes in structure. In addition, the same group of substances have varying abilities to inhibit bacterial luciferase competitively, although there is no correlation between anaesthetic and inhibition potency. The data do, however, show that closely related hydrophobic steroids are able to interfere with the catalytic activity of an enzyme selectively and, by inference, suggest that differences in anaesthetic potency could be a consequence of selective differences in ability to interact with a target protein.