20-The Cuban scorpion Rhopalurus junceus (Scorpiones, Buthidae): component variations in venom samples collected in different geographical areas

^ICenter for Mountain Development, Ministry of Science, Technology and Environment, Limonar de Monte Roux, El Salvador Guantánamo, Cuba

^IIDepartment of Molecular Medicine and Bioprocesses, Biotechnology Institute, National Autonomous University of Mexico, Cuernavaca, Mexico

^IIIDepartment of Biochemistry, School of Biology, University of Havana, Havana, Cuba

ABSTRACT

Backgound

The venom of the Cuban scorpion Rhopalurus junceus is poorly study from the point of view of their components at molecular level and the functions associated. The purpose of this article was to conduct a proteomic analysis of venom components from scorpions collected in different geographical areas of the country.

Results

Venom from the blue scorpion, as it is called, was collected separately from specimens of five distinct Cuban towns (Moa, La Poa, Limonar, El Chote and Farallones) of the Nipe-Sagua-Baracoa mountain massif and fractionated by high performance liquid chromatography (HPLC); the molecular masses of each fraction were ascertained by mass spectrometry analysis. At least 153 different molecular mass components were identified among the five samples analyzed. Molecular masses varied from 466 to 19755 Da. Scorpion HPLC profiles differed among these different geographical locations and the predominant molecular masses of their components. The most evident differences are in the relative concentration of the venom components. The most abundant components presented molecular weights around 4 kDa, known to be K⁺-channel specific peptides, and 7 kDa, known to be Na⁺-channel specific peptides, but with small molecular weight differences. Approximately 30 peptides found in venom samples from the different geographical areas are identical, supporting the idea that they all probably belong to the same species, with some interpopulational variations. Differences were also found in the presence of phospholipase, found in venoms from the Poa area (molecular weights on the order of 14 to 19 kDa). The only ubiquitous enzyme identified in the venoms from all five localities studied (hyaluronidase) presented the same 45 kD molecular mass, identified by gel electrophoresis analysis.

Conclusions

The venom of these scorpions from different geographical areas seem to be similar, and are rich in peptides that have of the same molecular masses of the peptides purified from other scorpions that affect ion-channel functions.

Key words: Cuba; Hyaluronidase; Peptides; Phospholipase; Proteomics; Rhopalurus junceus ; Scorpion

Received: October 30, 2012; Accepted: December 12, 2012

Competing interest The author declares no conflicts of interest.

Authors’ contributions RRR, student from the joint program UNAM-University of Habana, collected the scorpions and made most experiments assisted by specific technicians; FIVC, technician at UNAM, run all the HPLC separations; FZZ, run the mass spectrometry analysis; LGM helped conducted the hyaluronidase assays determination; GEL, tutor from the Habana University program, contributed on the design of experiments, assisted the student and helped writing the article; ARU contributed to the design of experiments, the collection and classification of scorpions; LDP, tutor from the UNAM university, designed the strategy of the work, supervised the conduction of all experiments and corrected the writing of the entire manuscript. All authors read and approved the final manuscript.

Correspondence: possani@ibt.unam.mx