Fig. 1. Dose-dependent inhibition of the activity of purified human wild-type CBS by sikokianin C and AOAA. (A) Chemical structure of sikokianin C. (B and C) The IC50 values of sikokianin C and AOAA against wild-type CBS were measured in the presence of 2 mM homocysteine, 2 mM cysteine, 5 μg of CBS protein, 0.4 mM lead nitrate, and varying concentrations of sikokianin C and AOAA in a 200 μL mixture (5% DMSO and 50 mM HEPES (pH 7.4)). The graph represents the relative activity of CBS in the presence of different concentrations of inhibitors compared with the activity of untreated CBS (control), and each data point is the mean ± SD (n = 3). GraphPad Prism 6 software was used to fit the data.
