Sea Anemone Peptide with Uncommon β-Hairpin Structure Inhibits Acid-sensing Ion Channel 3 (ASIC3) and Reveals Analgesic Activity

• Published in: The Journal of biological chemistry Vol. 288; no. 32; pp. 23116 - 23127
• Main Authors: Osmakov, Dmitry I., Kozlov, Sergey A., Andreev, Yaroslav A., Koshelev, Sergey G., Sanamyan, Nadezhda P., Sanamyan, Karen E., Dyachenko, Igor A., Bondarenko, Dmitry A., Murashev, Arkadii N., Mineev, Konstantin S., Arseniev, Alexander S., Grishin, Eugene V.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.08.2013; American Society for Biochemistry and Molecular Biology
• Subjects: Acid Sensing Ion Channels (ASIC); Acid Sensing Ion Channels - genetics; Acid Sensing Ion Channels - metabolism; Amino Acid Sequence; Analgesics - chemistry; Analgesics - isolation & purification; Analgesics - pharmacology; Animals; Gene Structure; Humans; Male; Mice; Molecular Sequence Data; Nuclear Magnetic Resonance; Pain - drug therapy; Pain - metabolism; Pain - pathology; Peptides; Peptides - chemistry; Peptides - genetics; Peptides - isolation & purification; Peptides - pharmacology; Protein Chemistry; Protein Purification; Protein Sequence; Protein Structure; Protein Structure and Folding; Protein Structure, Secondary; Sea Anemones - chemistry; Sea Anemones - genetics; Xenopus laevis; Protein Sequence; Nuclear Magnetic Resonance; Acid Sensing Ion Channels (ASIC); Protein Chemistry; Peptides; Gene Structure; Protein Purification; Protein Structure
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M113.485516

Three novel peptides were isolated from the venom of the sea anemone Urticina grebelnyi. All of them are 29 amino acid peptides cross-linked by two disulfide bridges, with a primary structure similar to other sea anemone peptides belonging to structural group 9a. The structure of the gene encoding the shared precursor protein of the identified peptides was determined. One peptide, π-AnmTX Ugr 9a-1 (short name Ugr 9-1), produced a reversible inhibition effect on both the transient and the sustained current of human ASIC3 channels expressed in Xenopus laevis oocytes. It completely blocked the transient component (IC50 10 ± 0.6 μm) and partially (48 ± 2%) inhibited the amplitude of the sustained component (IC50 1.44 ± 0.19 μm). Using in vivo tests in mice, Ugr 9-1 significantly reversed inflammatory and acid-induced pain. The other two novel peptides, AnmTX Ugr 9a-2 (Ugr 9-2) and AnmTX Ugr 9a-3 (Ugr 9-3), did not inhibit the ASIC3 current. NMR spectroscopy revealed that Ugr 9-1 has an uncommon spatial structure, stabilized by two S-S bridges, with three classical β-turns and twisted β-hairpin without interstrand disulfide bonds. This is a novel peptide spatial structure that we propose to name boundless β-hairpin. Background: Sea anemone peptides are promising tools for understanding physiological functions of ion channels. Results: A new peptide, Ugr 9-1, was isolated from the sea anemone venom and was shown to inhibit the acid-sensing ion channel 3 (ASIC3) channel. Conclusion: Ugr 9-1 affects the ASIC3 channel, produces analgesic effects, and has a unique spatial structure and mechanism of action. Significance: Ugr 9-1 represents a novel structural fold of natural short peptides modulating neuronal channels.