Publications by authors named "Juana Maria Jimenez Vargas"

Article Synopsis
  • A newly discovered "striped scorpion" species from Mexico is toxic to mammals and has potential therapeutic and biotechnological uses.
  • The study involved determining the lethal dose for mice and analyzing its secretory gland transcriptome and venom proteome using high-throughput sequencing and mass spectrometry.
  • The research identified 244 complete transcripts related to toxins and 70 venom components, making it the most comprehensive analysis of scorpion venom to date and providing new insights into venom biology.
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Scorpions are a group of arthropods that strike fear in many people due to their severe medical symptoms, even death, caused by their venomous stings. Even so, not all scorpion species contain harmful venoms against humans but still have valuable bioactive molecules, which could be used in developing new pharmaceutical leads for treating important diseases. This work conducted a comprehensive analysis of the venom from the scorpion Thorellius intrepidus.

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Skin secretions of toads are a complex mixture of molecules. The substances secreted comprise more than 80 different compounds that show diverse pharmacological activities. The compounds secreted through skin pores and parotid glands are of particular interest because they help toads to endure in habitats full of pathogenic microbes, i.

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Article Synopsis
  • The peptide Ct1a, a β-toxin made up of 66 amino acids, is derived from the venom of the scorpion species Centruroides tecomanus and is the most abundant toxin found in its venom.
  • Ct1a influences the spontaneous firing rate (SFR) of neurons in the suprachiasmatic nucleus (SCN) in a concentration-dependent manner, significantly increasing it at 100 nM but decreasing it at higher concentrations (500 nM and 1000 nM).
  • The study indicates that Ct1a affects the SFR of SCN neurons by altering the properties of hNav1.6 sodium channels, shifting their activation to more negative potentials and reducing peak current amplitudes.
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Six peptides, belonging to the NDBP-4 family of scorpion antimicrobial peptides were structurally and functionally characterized. The sequence of the mature peptides VpCT1, VpCT2, VpCT3 and VpCT4 was inferred by transcriptomic analysis of the venom gland of the scorpion Mesomexovis variegatus. Analysis of their amino acid sequences revealed patterns that are also present in previously reported peptides that show differences in their hemolytic and antimicrobial activities in vitro.

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Article Synopsis
  • The Helodermatidae family of lizards includes two main species known for their venomous secretions: Heloderma horridum horridum and Heloderma suspectum suspectum.
  • Researchers used RNA sequencing (RNA-seq) to analyze the venom glands of H. horridum horridum, discovering over 114,000 transcripts with 199 annotated based on previous studies.
  • The study identified various highly expressed proteins in the venom, including exendins, defensins, and serine protease inhibitors, which could enhance our understanding of their venom and its biological effects.
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Centruroides hirsutipalpus (Scorpiones: Buthidae) is related to the "striped scorpion" group inhabiting the western Pacific region of Mexico. Human accidents caused by this species are medically important due to the great number of people stung and the severity of the resulting intoxication. This communication reports an extensive venom characterization using high-throughput proteomic and Illumina transcriptomic sequencing performed with RNA purified from its venom glands.

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To understand the diversity of scorpion venom, RNA from venomous glands from a sawfinger scorpion, , of the family Vaejovidae, was extracted and used for transcriptomic analysis. A total of 84,835 transcripts were assembled after Illumina sequencing. From those, 119 transcripts were annotated and found to putatively code for peptides or proteins that share sequence similarities with the previously reported venom components of other species.

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Article Synopsis
  • A new alkaloid has been discovered in the venom of the Mexican scorpion Megacormus gertschi, differing from the previously known peptidic and proteinic components.
  • Nuclear magnetic resonance and mass spectrometry were used to determine its structure, (Z)-N-(2-(1H-imidazol-4-yl)ethyl)-3-(4-hydroxy-3-methoxyphenyl)-2-methoxyacrylamide (1).
  • Despite its abundance in venom, the alkaloid does not exhibit insecticidal activity, but its unique structure suggests potential medicinal properties worth exploring.
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Arthropod venoms are a rich mixture of biologically active compounds exerting different physiological actions across diverse phyla and affecting multiple organ systems including the central nervous system. Venom compounds can inhibit or activate ion channels, receptors and transporters with high specificity and affinity providing essential insights into ion channel function. In this review, we focus on arthropod toxins (scorpions, spiders, bees and centipedes) acting on neuronal potassium channels.

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Venom from male and female scorpions of the species Centruroides limpidus were separated by HPLC and their molecular masses determined by mass spectrometry. The relative concentration of components eluting in equivalent retention times from the HPLC column shows some differences. A new peptide with 29 amino acids, cross-linked by three disulfide bonds was found in male scorpions and its structure determined.

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Article Synopsis
  • The study focuses on the antimicrobial effects of two new peptides, VpAmp1.0 and VpAmp2.0, derived from the venom of the Mexican scorpion Vaejovis punctatus.
  • Both peptides, along with their shorter variants, showed effectiveness against various microorganisms, including strains resistant to traditional antibiotics, indicating potential as new antimicrobial agents.
  • The research reveals that these peptides can inhibit the growth of Gram-positive and Gram-negative bacteria, as well as fungi, with minimum inhibitory concentrations (MICs) ranging from 2.5 to 50.0 μM, highlighting the importance of their unique amino acid structures.
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Article Synopsis
  • UyCT peptides are antimicrobial peptides from Australian scorpion venom that show effectiveness against various bacteria, including multi-drug resistant strains.
  • Their interaction with membranes was analyzed using techniques like dye release and isothermal titration calorimetry, revealing a mechanism that disrupts bacterial membranes while minimizing damage to red blood cells.
  • The findings suggest that UyCT peptides could be developed into treatments for resistant bacterial infections, particularly targeting pathogens such as Acinetobacter baumannii, with potential for improving their delivery and safety profiles.
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Background: Microbial antibiotic resistance is a challenging medical problem nowadays. Two scorpion peptides displaying antibiotic activity: hadrurin and vejovine were taken as models for the design of novel shorter peptides with similar activity.

Methods: Using the standard Fmoc-based solid phase synthesis technique of Merrifield twelve peptides (18 to 29 amino acids long) were synthesized, purified and assayed against a variety of multi-drug resistant Gram-negative bacteria from clinical isolates.

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Scorpion γ-KTx toxins are important molecular tools for studying physiological and pharmacological functions of human ether-á-go-go related gene (hERG) K(+) channels. To pinpoint functional residues of this class of toxins involved in channel binding, we employed a combined approach that integrates evolutionary information and site-directed mutagenesis. Among three positively selected sites (PSSs) identified here, two (Gln18 and Met35) were found to be associated with the toxin's function because their changes significantly decreased the potency of ErgTx1 (also called CnErg1) on hERG1 channel.

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Article Synopsis
  • Researchers identified four new antimicrobial peptides from scorpion venom glands of two species in the Vaejovidae family.
  • These peptides, each consisting of 13 amino acids, share similarities with known antimicrobial peptides but exhibit different biological activities.
  • VmCT1 and VmCT2 demonstrated broad-spectrum antibacterial effects with low hemolytic activity, and the study discusses the factors influencing their varying activities.
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