Isolation and structural identification of a new T1-conotoxin with unique disulfide connectivities derived from Conus bandanus
J. venom. anim. toxins incl. trop. dis
;
26: e20190095, 2020. tab, graf, ilus
Artículo
en Inglés
| LILACS, VETINDEX
| ID: biblio-1135162
ABSTRACT
Conopeptides are neuropharmacological peptides derived from the venomous salivary glands of cone snails. Among 29 superfamilies based on conserved signal sequences, T-superfamily conotoxins, which belong to the smallest group, include four different frameworks that contain four cysteines denominated I, V, X and XVI. In this work, the primary structure and the cysteine connectivity of novel conotoxin of Conus bandanus were determined by tandem mass spectrometry using collision-induced dissociation. Methods:
The venom glands of C. bandanus snails were dissected, pooled, and extracted with 0.1% trifluoroacetic acid in three steps and lyophilized. The venom was fractionated and purified in an HPLC system with an analytical reversed-phase C18 column. The primary peptide structure was analyzed by MALDI TOF MS/MS using collision-induced dissociation and confirmed by Edman's degradation. The peptide's cysteine connectivity was determined by rapid partial reduction-alkylation technique.Results:
The novel conotoxin, NGC1C2(I/L)VREC3C4, was firstly derived from de novo sequencing by MS/MS. The presence of isoleucine residues in this conotoxin was confirmed by the Edman degradation method. The conotoxin, denominated Bn5a, belongs to the T1-subfamily of conotoxins. However, the disulfide bonds (C1-C4/C2-C3) of Bn5a were not the same as found in other T1-subfamily conopeptides but shared common connectivities with T2-subfamily conotoxins. The T1-conotoxin of C. bandanus proved the complexity of the disulfide bond pattern of conopeptides. The homological analysis revealed that the novel conotoxin could serve as a valuable probe compound for the human-nervous-system norepinephrine transporter.Conclusion:
We identified the first T1-conotoxin, denominated Bn5a, isolated from C. bandanus venom. However, Bn5a conotoxin exhibited unique C1-C4/C2-C3 disulfide connectivity, unlike other T1-conotoxins (C1-C3/C2-C4). The structural and homological analyses herein have evidenced novel conotoxin Bn5a that may require further investigation.(AU)
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Péptidos
/
Conotoxinas
/
Disulfuros
/
Caracol Conus
Tipo de estudio:
Estudio diagnóstico
Límite:
Animales
Idioma:
Inglés
Revista:
J. venom. anim. toxins incl. trop. dis
Año:
2020
Tipo del documento:
Artículo
Institución/País de afiliación:
Institut de Chimie des Substances Naturelles/FR
/
Nha Trang University/VN
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