A K⁺ channel blocking peptide from the Cuban scorpion Rhopalurus garridoi

Rodolfo Rodríguez-Ravelo; Rita Restano-Cassulini; Fernando Z Zamudio; Fredy I V Coronas; Georgina Espinosa-López; Lourival D Possani

doi:10.1016/j.peptides.2013.10.010

A K⁺ channel blocking peptide from the Cuban scorpion Rhopalurus garridoi

Peptides. 2014 Mar:53:42-7. doi: 10.1016/j.peptides.2013.10.010. Epub 2013 Oct 25.

Authors

Rodolfo Rodríguez-Ravelo¹, Rita Restano-Cassulini², Fernando Z Zamudio³, Fredy I V Coronas⁴, Georgina Espinosa-López⁵, Lourival D Possani⁶

Affiliations

¹ Center for Mountain Development, Ministry of Science, Technology and, Environment, Limonar de Monte Roux, El Salvador Guantánamo, Cuba. Electronic address: rodolfo@cdm.gtmo.inf.cu.
² Department of Molecular Medicine and Bioprocesses, Biotechnology, Institute, National Autonomous University of Mexico, Avenida Universidad 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca, Morelos 62210, Mexico. Electronic address: rita@ibt.unam.mx.
³ Department of Molecular Medicine and Bioprocesses, Biotechnology, Institute, National Autonomous University of Mexico, Avenida Universidad 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca, Morelos 62210, Mexico. Electronic address: zam@ibt.unam.mx.
⁴ Department of Molecular Medicine and Bioprocesses, Biotechnology, Institute, National Autonomous University of Mexico, Avenida Universidad 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca, Morelos 62210, Mexico. Electronic address: fredy@ibt.unam.mx.
⁵ Department of Biochemistry, School of Biology, University of Havana, Havana, Cuba. Electronic address: georgina@fbio.uh.cu.
⁶ Department of Molecular Medicine and Bioprocesses, Biotechnology, Institute, National Autonomous University of Mexico, Avenida Universidad 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca, Morelos 62210, Mexico. Electronic address: possani@ibt.unam.mx.

PMID: 24512947
DOI: 10.1016/j.peptides.2013.10.010

Abstract

A proteomic analysis of the venom obtained from the Cuban scorpion Rhopalurus garridoi was performed. Venom was obtained by electrical stimulation, separated by high performance liquid chromatography, and the molecular masses of their 50 protein components were identified by mass spectrometry. A peptide of 3940 Da molecular mass was obtained in pure form and its primary structure determined. It contains 37 amino acid residues, including three disulfide bridges. Electrophysiological experiments showed that this peptide is capable of blocking reversibly K(+)-channels hKv1.1 with a Kd close to 1 μM, but is not effective against hKv1.4, hERG1 and EAG currents, at the same concentration. This is the first protein component ever isolated from this species of scorpion and was assigned the systematic number α-KTx 2.14.

Keywords: Amino acid sequence; K(+)-channel; Proteome; Rhopalurus garridoi; Scorpion venom.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Chromatography, High Pressure Liquid
Electrophysiology
Mass Spectrometry
Peptides / chemistry*
Peptides / metabolism
Peptides / pharmacology
Potassium Channel Blockers / chemistry*
Potassium Channel Blockers / metabolism
Potassium Channel Blockers / pharmacokinetics
Potassium Channels / drug effects
Proteomics
Scorpion Venoms / chemistry*
Scorpion Venoms / metabolism
Scorpion Venoms / pharmacology
Scorpions / metabolism*

Substances

Peptides
Potassium Channel Blockers
Potassium Channels
Scorpion Venoms