Fig. 2.

In vitro inhibition of retinoid isomerase activity by MB compounds. Primary amines were preincubated with bovine RPE microsomes at room temperature for 5 minutes, then all-trans-retinol was added, and the mixtures were incubated at 37°C. After 1 hour of incubation, all reactions were quenched by the addition of methanol. Inhibition of RPE65 enzymatic activity was measured as a decline in 11-cis-retinol production. (A) Production of 11-cis-retinol in the presence of amines designed to inhibit RPE65. The IC₅₀ values for emixustat and (R)-MB-001 in this assay are 232 ± 3 and 396 ± 58 nM, respectively (Kiser et al., 2015). (B) Production of 11-cis-retinol in the presence of amines with bulky groups that could hinder RPE65 active-site binding. Chiral centers are marked with asterisks.