μ-Conotoxin GIIIB

μ-Conotoxin GIIIB, a 22-residue polypeptide derived from the venom of the piscivorous cone snail Conus geographus, serves as an inhibitor of the Na V 1.4 channel, effectively blocking muscle cell contraction [1] [2] [3].

O=C1[C@]2(N(C(=O)[C@]([C@@H](C)O)(NC(=O)[C@]3(NC(=O)[C@@H](NC([C@@H](NC([C@H](CCCNC(=N)N)N)=O)CC(O)=O)=O)CSSC[C@]4(C(=O)N[C@@H](CCCCN)C(=O)N5[C@](C(=O)N[C@@H](CCSC)C(=O)N[C@@H](CCCCN)C(=O)N[C@@](CSSC3)(C(=O)N[C@H](C(N[C@H](C(N)=O)C)=O)CSSC[C@](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@]6(N1C[C@H](O)C6)[H])(C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(O)=O)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N4)[H])[H])(C[C@@H](O)C5)[H])[H])[H])[H])C[C@H](O)C2)[H]