title: Kunitz-Type Peptide HCRG21 from the Sea Anemone Heteractis crispa Is a Full Antagonist of the TRPV1 Receptor.
abstract: Sea anemone venoms comprise multifarious peptides modulating biological targets such as ion channels or receptors. The sequence of a new Kunitz-type peptide, HCRG21, belonging to theHeteractis crispaRG (HCRG) peptide subfamily was deduced on the basis of the gene sequence obtained from theHeteractis crispacDNA. HCRG21 shares high structural homology with Kunitz-type peptides APHC1-APHC3 fromH. crispa, and clusters with the peptides from so named "analgesic cluster" of the HCGS peptide subfamily but forms a separate branch on the NJ-phylogenetic tree. Three unique point substitutions at the N-terminus of the molecule, Arg1, Gly2, and Ser5, distinguish HCRG21 from other peptides of this cluster. The trypsin inhibitory activity of recombinant HCRG21 (rHCRG21) was comparable with the activity of peptides from the same cluster. Inhibition constants for trypsin and α-chymotrypsin were 1.0 × 10-7and 7.0 × 10-7M, respectively. Electrophysiological experiments revealed that rHCRG21 inhibits 95% of the capsaicin-induced current through transient receptor potential family member vanilloid 1 (TRPV1) and has a half-maximal inhibitory concentration of 6.9 ± 0.4 μM. Moreover, rHCRG21 is the first full peptide TRPV1 inhibitor, although displaying lower affinity for its receptor in comparison with other known ligands. Macromolecular docking and full atom Molecular Dynamics (MD) simulations of the rHCRG21-TRPV1 complex allow hypothesizing the existence of two feasible, intra- and extracellular, molecular mechanisms of blocking. These data provide valuable insights in the structural and functional relationships and pharmacological potential of bifunctional Kunitz-type peptides.
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. rita1950@mail.ru.
authors.forename: Margarita
authors.initials: M
authors.lastname: Monastyrnaya
authors.affiliation: Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, Leuven B-3000, Belgium. Steve.Peigneur@pharm.kuleuven.be.
authors.forename: Steve
authors.initials: S
authors.lastname: Peigneur
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. zel01@mail.ru.
authors.forename: Elena
authors.initials: E
authors.lastname: Zelepuga
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. sintsova0@gmail.com.
authors.forename: Oksana
authors.initials: O
authors.lastname: Sintsova
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. irinagladkikh@gmail.com.
authors.forename: Irina
authors.initials: I
authors.lastname: Gladkikh
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. 969844@gmail.com.
authors.forename: Elena
authors.initials: E
authors.lastname: Leychenko
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. issaeva@gmail.com.
authors.forename: Marina
authors.initials: M
authors.lastname: Isaeva
authors.affiliation: Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, Leuven B-3000, Belgium. jan.tytgat@pharm.kuleuven.be.
authors.forename: Jan
authors.initials: J
authors.lastname: Tytgat
authors.affiliation: G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia. kozempa@mail.ru.
authors.forename: Emma
authors.initials: E
authors.lastname: Kozlovskaya
mesh_terms: D000595:Amino Acid Sequence; D000700:Analgesics / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002918:Chymotrypsin / Q000737:chemistry / Q000494:pharmacology; D003064:Cnidarian Venoms / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D012615:Sea Anemones / Q000737:chemistry*; D016415:Sequence Alignment; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors*
chemical_list: D000700:Analgesics; D003064:Cnidarian Venoms; D010455:Peptides; D050916:TRPV Cation Channels; C494484:TRPV1 receptor; D002918:Chymotrypsin; C117608:alpha-chymotrypsin
keywords: Cnidaria; Kunitz-type peptides; TRPV1; electrophysiology; sea anemone