Figure 12.

Modeling of the conversion of dihydrolanosterol to dihydro FF-MAS and effects of changing only two k_offrate constants. The rate constants for the dissociation of 14α-CH₂OH dihydrolanosterol and 14α-CHO dihydrolanosterol (Table 1) were increased 10-, 100-, and 1000-fold, keeping all other rate constants constant (Table 1). The predicted changes are shown: A, k_cat; B, K_m; C, k_cat/K_m; D, K_i for an inhibitor included with a K_d of 25 nM. E, the predicted effect of a K_d 25 nM inhibitor is also shown in an IC₅₀ plot (using 10 μM dihydrolanosterol) (black line, ●, 1 × ; green line, □, 10 × ; red line, ■, 100 × ; blue line, ▲, −1000 × ). The respective modeled IC₅₀ values were 2.60, 1.17, 1.10, and 0.95 μM. FF-MAS, follicular fluid meiosis-activating sterol ((4β,5α)-4,4-dimethyl-cholesta-8,14,24-trien-3-ol).