Inhibition ofent-Kaurene Synthase by Quaternary Ammonium Growth Retardants

Abstract

The effect of fourteen quaternary ammonium iodides on ent- kaurene synthase from Cucurbita maxima L. was examined. Structure-dependent inhibition of the overall ΑΒ activity of ent- kaurene synthase was found, but only weak or no inhibition on В activity, suggesting that the site of inhibition was ent-kaurene synthase A. N, N, N-Trimethyl-l-methyl-(2ʹ, 2, 4ʹ, 6ʹ-tetramethyl- cyclohex-3ʹ-en-r-yl)prop-2-enylammonium iodide, which has structural similarity to geranylgeranyl pyrophosphate, reduced AB activity to 50% of the control value at a concentration of 0.1 μΜ.