Cy5-ProTx-II is a Cy5 fluorescently labeled ProTx-II, a famous Nav1.7 blocker. The wild type ProTx-II potently blocks Nav1.7 with an IC50 value of around 300 pM, Nav1.2, Nav1.5 and Nav1.6 with IC50 values of 41 nM, 79 nM and 26 nM respectively. It was shown to fully block Nav1.7 at 100 nM concentration. Cy5: λex 646nm , λem 662nm.
Peptides & proteins
Protoxin II, ProTx 2
Fluorescent Nav1.7 channel blocker
Middleton R. E., et al. (2002) Two tarantula peptides inhibit activation of multiple sodium channels, Biochemistry. PMID: 12475222
AA sequence: Tyr-Cys2-Gln-Lys-Trp-Met-Trp-Thr-Cys9-Asp-Ser-Glu-Arg-Lys-Cys15-Cys16-Glu-Gly-Met-Val-Cys21-Arg-Leu-Trp-Cys25-Lys-Lys-Lys-Leu-Trp-OH. Disulfide bonds: Cys2-Cys16, Cys9-Cys21, Cys15-Cys25