Loxosceles intermedia venom comprises a complex mixture of proteins, glycoproteins and low molecular mass peptides that act synergistically to immobilize envenomed prey. Analysis of a venom-gland transcriptome from L. intermedia revealed that knottins, also known as inhibitor cystine knot peptides, are the most abundant class of toxins expressed in this species. Knottin peptides contain a particular arrangement of intramolecular disulphide bonds, and these peptides typically act upon ion channels or receptors in the insect nervous system, triggering paralysis or other lethal effects. Herein, we focused on a knottin peptide with 53 amino acid residues from L. intermedia venom. The recombinant peptide, named U -sicaritoxin-Li1b (Li1b), was obtained by expression in the periplasm of Escherichia coli. The recombinant peptide induced irreversible flaccid paralysis in sheep blowflies. We screened for knottin-encoding sequences in total RNA extracts from two other Loxosceles species, Loxosceles gaucho and Loxosceles laeta, which revealed that knottin peptides constitute a conserved family of toxins in the Loxosceles genus. The insecticidal activity of U -SCTX-Li1b, together with the large number of knottin peptides encoded in Loxosceles venom glands, suggests that studies of these venoms might facilitate future biotechnological applications of these toxins.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/imb.12268 | DOI Listing |
Int J Biol Macromol
November 2024
Department of Cell Biology, Federal University of Paraná (UFPR), Curitiba 81530-900, PR, Brazil. Electronic address:
Spiders of Loxosceles genus, or Brown spiders produce a potent venom with minimal volume and protein content. Among its toxins, phospholipases D (PLDs) are notable for causing primary local and systemic manifestations observed following envenomation. They degrade cellular phospholipids, mainly sphingomyelin and lysophosphatidylcholine.
View Article and Find Full Text PDFJ Venom Anim Toxins Incl Trop Dis
July 2024
Department of Veterinary Clinic and Surgery, Veterinary College, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.
Background: Loxoscelism refers to a set of clinical manifestations caused by the bite of spiders from the genus. The classic clinical symptoms are characterized by an intense inflammatory reaction at the bite site followed by local necrosis and can be classified as cutaneous loxoscelism. This cutaneous form presents difficult healing, and the proposed treatments are not specific or effective.
View Article and Find Full Text PDFCells
June 2024
Department of Cell Biology, Federal University of Paraná, Curitiba 81531-980, PR, Brazil.
In the original publication [...
View Article and Find Full Text PDFToxicon
August 2024
Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, 852-8521, Japan.
Pufferfish saxitoxin- and tetrodotoxin (TTX)-binding protein (PSTBP) is considered to transfer TTX between tissues. The immunohistochemical distribution of PSTBP-homolog (PSTBPh) and TTX in the brain and pituitary of hatchery-reared juvenile tiger puffer Takifugu rubripes was investigated. PSTBPh was observed mainly in the pars intermedia of the pituitary.
View Article and Find Full Text PDFBMC Genomics
December 2023
Department of Venomous Animals and Anti-Venom Production, Agricultural Research, Education and Extension Organization (AREEO), Razi Vaccine and Serum Research Institute, Ahvaz, Iran.
Background: Venom phospholipase D (PLDs), dermonecrotic toxins like, are the major molecules in the crude venom of scorpions, which are mainly responsible for lethality and dermonecrotic lesions during scorpion envenoming. The purpose of this study was fivefold: First, to identify transcripts coding for venom PLDs by transcriptomic analysis of the venom glands from Androctonus crassicauda, Hottentotta saulcyi, and Hemiscorpius lepturus; second, to classify them by sequence similarity to known PLDs and motif extraction method; third, to characterize scorpion PLDs; fourth to structural homology analysis with known dermonecrotic toxins; and fifth to investigate phylogenetic relationships of the PLD proteins.
Results: We found that the venom gland of scorpions encodes two PLD isoforms: PLD1 ScoTox-beta and PLD2 ScoTox-alpha I.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!