Fig. 7: Identification of rosmarinic acid as an agonist of PRDX1.
a Identification of rosmarinic acid (RA) as a potential agonist of PRDX1. Protein thermal shift assay (PTS) was used to identify 6 hits and RA shows the highest efficacy in activating PRDX1’s peroxidase activity as reflected by in vitro peroxidase activity assay. For more details, please see the Methods section. Hits are marked as red dots, while others are shown as black dots. Blue dashed lines represent the same positive values of ΔTmD and ΔTmB. ΔTmD, derivative delta melting temperature; ΔTmB, Boltzmann delta melting temperature; LA, lawsone; MO, morine; SB, Salvianolic acid B; EG, Epigallocatechin Gallate; PH, Phloracetophenone. b Half maximal concentration of RA for activating WT PRDX1’s peroxidase activity. For a and b, data are presented as means ± SEM from three independent experiments. c Binding affinity of RA with WT PRDX1 by SPR assay. The dissociation constant (KD) is shown as means ± SEM from duplicate experiments. d Unbiased FO-FC density map contoured at 2.5σ of RA in RA-PRDX1C52SC83S (aa1-175) complex structure. RA is shown in yellow stick. Maps are shown in blue nets. e 2FO-FC density map of RA and neighboring residues of PRDX1 in RA- PRDX1C52SC83S (aa 1-175) complex structure. RA is shown in yellow stick. Maps are shown in gray nets. Waters are shown in red spheres. Chain A and chain B are shown in green and navy cartoon, respectively. Residues near RA are also shown as sticks. f Complex crystal structure showing that RA binds at the peroxidatic site of PRDX1C52SC83S (aa 1-175). The peroxidatic site is highlighted in salmon stick. RA, Chain A and Chain B are shown as in (e). g Electrostatic potential of RA-PRDX1 C52SC83S (aa 1-175) complex crystal structure and RA binding site. The interior of RA’s binding site is electronegative (colored in blue), while the exterior is electropositive (colored in red). h Hydrogen bond network formed between RA and residues in the binding pocket. Residues around 5 Å of RA are shown in stick. Waters are shown in red spheres. Hydrogen bonds are shown in magenta dashed lines.
