FIGURE 4

Peptide-protein docking analysis and fluorescent calcium measurement. (A). Side view of protein-peptide docking of the APHC1 peptide binding to the TRPV1 channel. The peptide is shown as a ribbon diagram colored in orange; the protein is shown as a cartoon. (B). Interface residues between APHC1 peptide and the TRPV1 channel. APHC1 peptide is shown in orange cartoon. In α chain, the hydrogen bonds are formed by Arg 18 and Arg 48 of APHC1 peptide with residue Ser 592 and Asn 628, respectively. In β chain, the hydrogen bonds are formed by Lys 28 and Arg 48 of APHC1 peptide with residue Cys 442 and Try 453, respectively. (C). Side view of protein-peptide docking of the PcActx peptide binding to the TRPV1 channel. The peptide is shown as a ribbon diagram colored in orange; the protein is shown as a cartoon. (D). Interface residues between PcActx peptide and the TRPV1 channel. PcActx peptide is shown in orange cartoon. The hydrogen bonds are formed by Tyr12, Gly17, Cys19, and Gln21 of PcActx peptide with residue Gln423, Arg701, Gln560 in γ chain, and Cys578 in δ chain of TRPV1, respectively. (E). Representative images of intracellular calcium concentration of HEK293-hTRPV1 cell (CAP: capsaicin; CPZ: capsazepine). (F). Representative time-dependent response of Ca²⁺ fluorescence intensity in each group. Ca²⁺ responses were measured as changes in fluorescence intensity of the representative average plots (n = 5) before (F₀) and after capsaicin addition (F). (E,F) graphs represent a single representative experiment from a total of three independent experiments.