A new PLA2 (F16) was purified from Crotalus durissus terrificus venom by molecular exclusion chromatography followed by analytical reverse phase HPLC. The PLA2 (14.86 kDa by MALDI-TOF mass spectrometry) had an amino acid sequence of SLLQFNKMIKFETRKNAVPFYAFYGCYCGWGGRRRPKDATDRCCFVHDCCYEKVTKCNTKWDIYRYSLKSGYITCGKGTWCKEQICECDRVAAECLRRSLSTYKNGYMFYPDSRCRGPSETC, and showed highly conserved Ca2+-binding and catalytic sites. F16 showed allosteric behavior with 10 mM Ca2+ and had temperature and pH optima of 25 degrees C and 7.9, respectively. F16 (10 microg/ml) produced neuromuscular blockade in chick biventer cervicis preparations in the absence and presence of crotapotin, indicating that crotapotin was not essential for neuromuscular action in this preparation. In contrast, in mouse phrenic nerve-diaphragm preparations, the neuromuscular blockade produced by the same concentration of toxin was dependent on crotapotin. Pre-incubation with heparin markedly reduced the neurotoxicity of F16. These results show that the biochemical and structural properties of F16 are similar to those of the PLA2 isoforms F15 and F17, but that the neurotoxicity and the requirement for crotapotin to form the crotoxin complex varies according to the neuromuscular preparation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s10930-005-6718-z | DOI Listing |
Pharmaceuticals (Basel)
January 2025
Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo (UNOESTE), Presidente Prudente 19050-680, SP, Brazil.
We compared the enzymatic, coagulant, and neuromuscular activities of two variants (yellow-CDRy and white-CDRw) of venom with a sample of (CDT) venom and examined their neutralization by antivenom against CDT venom. The venoms were screened for enzymatic and coagulant activities using standard assays, and electrophoretic profiles were compared by SDS-PAGE. Neutralization was assessed by preincubating venoms with crotalic antivenom and assaying the residual activity.
View Article and Find Full Text PDFJ Exp Biol
January 2025
Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Peripheral arterial chemoreceptors monitor the levels of arterial blood gases and adjust ventilation and perfusion to meet metabolic demands. These chemoreceptors are present in all vertebrates studied to date but have not been described fully in reptiles other than turtles. The goals of this study were to 1) identify functional chemosensory areas in the South American rattlesnake (Crotalus durissus) 2) determine the neurochemical content of putative chemosensory cells in these areas and 3) determine the role each area plays in ventilatory and cardiovascular control.
View Article and Find Full Text PDFToxicon
January 2025
Teaching and Research Center, Francisca Mendes Heart Hospital Foundation, Manaus, 69097-720, Brazil; Research management, Hospital Foundation of Hematology and Hemotherapy of Amazonas, 69050-001, Brazil. Electronic address:
We evaluated the efficacy of freeze-dried Bothrops-Lachesis-Crotalus antivenom and liquid Crotalus antivenoms to neutralize Crotalus durissus ruruima (Cdr) venom (Roraima, Brazil) comparing with C. d. terrificus (Cdt) venom.
View Article and Find Full Text PDFCurr Protein Pept Sci
November 2024
Laboratório de Imunologia Celular Aplicada à Saúde, Fundação Oswaldo Cruz, FIOCRUZ Rondônia, Porto Velho-RO, Brazil.
Background: Crotalus Neutralizing Factor (CNF) is a γ-type Phospholipase A2 (PLA2) inhibitor present in the blood of Crotalus durissus terrificus snake. Particularly, CNF inhibits the toxic action of Crotoxin (CTX), which is a major neurotoxin found in C. d.
View Article and Find Full Text PDFRev Soc Bras Med Trop
October 2024
Universidade Federal do Ceará, Hospital Universitário Walter Cantídio, Fortaleza, CE, Brasil.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!