Fig. 2

Predicted binding modes of ZnPcS at HSA. a Distribution of docking scores for conformer clusters. The 500 binding conformers of ZnPcS were clustered based on their root-mean-square deviations (RMSDs). The point color and size depend on the cluster size. The conformers with the lowest energy score and the most densely populated conformers are named conformer 1 and conformer 2, respectively. b The conformers with the lowest energy scores are represented by sticks with their carbon atoms in purple. c The most highly populated conformers are displayed in sticks with their carbon atoms in sky blue. d The binding mode of ZnPcS at the heme site (conformer 1) of HSA. e The other possible binding mode of ZnPcS at the cleft region (conformer 2). The protein surface is colored according to its electrostatic potential, and the bound compound is represented by its carbon atoms in magenta. In the enlarged view, the compound is displayed by a ball-and-stick model, and the key residues that interact with the compounds are shown as thin sticks with their carbon atoms in light blue. The dative bond between the Zn²⁺ atom (shown in the purple sphere) and Y161 or D187 is indicated by black lines, and the ionic interactions are indicated by black dashed lines