Recombinant expression and antigenicity of two peptide families of neurotoxins from Androctonus sp

Background: Scorpion neurotoxins such as those that modify the mammalian voltagegated sodium ion channels (Nav) are the main responsible for scorpion envenomation. Their neutralization is crucial in the production of antivenoms against scorpion stings. Methods: In the present study, two in silico designed genes ­ one that codes for a native neurotoxin from the venom of the Anatolian scorpion Androctonus crassicauda, named Acra 4 ­ and another non-native toxin ­ named consensus scorpion toxin (SccTx) obtained from the alignment of the primary structures of the most toxic neurotoxins from the Middle Eastern and North African scorpions ­ were recombinantly expressed in E. coli Origami. Results: Following bacterial expression, the two expressed neurotoxins, hereafter named HisrAcra4 and HisrSccTx, were obtained from inclusion bodies. Both recombinant neurotoxins were obtained in multiple Cys-Cys isoforms. After refolding, the active protein fractions were identified with molecular masses of 8,947.6 and 9,989.1 Da for HisrAcra4 and HisrSccTx, respectively, which agreed with their expected theoretical masses. HisrAcra4 and HisrSccTx were used as antigens to immunize two groups of rabbits, to produce either anti-HisrAcra4 or anti-HisrSccTx serum antibodies, which in turn could recognize and neutralize neurotoxins from venoms of scorpion species from the Middle East and North Africa. The antibodies obtained from rabbits neutralized the 3LD50 of Androctonus australis, Leiurus quinquestriatus hebraeus and Buthus occitanus venoms, but they did not neutralize A. crassicauda and A. mauritanicus venoms. In addition, the anti-HisrAcra4 antibodies did not neutralize any of the five scorpion venoms tested. However, an antibody blend of anti-HisrAcra4 and anti-HisrSccTx was able to neutralize A. crassicauda and A. mauritanicus venoms. Conclusions: Two recombinant Nav neurotoxins, from different peptide families, were used as antigens to generate IgGs for neutralizing scorpion venoms of species from the Middle East and North Africa.(AU)

ß-micrustoxin (Mlx-9), a PLA2 from Micrurus lemniscatus snake venom: biochemical characterization and anti-proliferative effect mediated by p53

Background: Endogenous phospholipases A2 (PLA2 ) play a fundamental role in inflammation, neurodegenerative diseases, apoptosis and cellular senescence. Neurotoxins with PLA2 activity are found in snake venoms from the Elapidae and Viperidae families. The mechanism of action of these neurotoxins have been studied using hippocampal and cerebellar neuronal cultures showing [Ca2+]i increase, mitochondrial depolarization and cell death. Astrocytes are rarely used as a model, despite being modulators at the synapses and responsible for homeostasis and defense in the central nervous system. Preserving the cell division ability, they can be utilized to study the cell proliferation process. In the present work cultured astrocytes and glioblastoma cells were employed to characterize the action of ß-micrustoxin (previously named Mlx-9), a PLA2 isolated from Micrurus lemniscatus snake venom. The ß-micrustoxin structure was determined and the cell proliferation, cell cycle phases and the regulatory proteins p53, p21 and p27 were investigated. Methods: ß-micrustoxin was characterized biochemically by a proteomic approach. Astrocytes were obtained by dissociation of pineal glands from Wistar rats; glioblastoma tumor cells were purchased from ATCC and Sigma and cultured in DMEM médium. Cell viability was evaluated by MTT assay; cell proliferation and cell cycle phases were analyzed by flow cytometry; p53, p21 and p27 proteins were studied by western blotting and immunocytochemistry. Results: Proteomic analysis revealed fragments on ß-micrustoxin that aligned with a PLA2 from Micrurus lemniscatus lemniscatus previously identified as transcript ID DN112835_C3_g9_i1/m.9019. ß-micrustoxin impaired the viability of astrocytes and glioblastoma tumor cells. There was a reduction in cell proliferation, an increase in G2/M phase and activation of p53, p21 and p27 proteins in astrocytes. Conclusion: These findings indicate that ß-micrustoxin from Micrurus lemniscatus venom could inhibit cell proliferation through p53, p21 and p27 activation thus imposing cell cycle arrest at the checkpoint G2/M.(AU)

Surto de botulismo tipo C em aves de subsistência em Santa Catarina, Brasil / Outbreak of type C botulism in backyard poultry in Santa Catarina, Brazil

Background: Botulism is a disease caused by the ingestion of neurotoxin produced by Clostridium botulinum, characterizedby flaccid paralysis, which can lead to high mortality. They have seven types of neurotoxins (A, B, C, D, E, F, and G) and,in birds, most cases are attributed to type C. They are considered sources of botulinum toxins where the decomposition oforganic matter occurs, like stagnant water and rotting food. The main feature of the disease in birds is ascending symmetricflaccid paralysis. The present study aims to describe an outbreak of type C botulism in backyard poultry in the state ofSanta Catarina, Southern Brazil.Case: A visit was made to the property with 160 backyard poultry with a history of high mortality in the municipality ofAgrolândia, Santa Catarina. Clinical signs were characterized by paralysis of the pelvic limbs, neck and pendular wings,which progressed to death within 48 h. There was a mortality rate of 37.5% (60/160) between March and May 2019. Thesebirds were kept in an overcrowded environment, with different species (chickens, ducks, teals, and turkeys) fed irregularly.The water supplied was provided from kitchen exhaust, accumulating in puddles on the floor that contained organic matterresidues such as animal feces, food waste and bone fragments. The disposal of the carcasses of birds that died was in thesame enclosure, buried superficially, facilitating the access of other birds to dig them up and consume them. Necropsywas performed on 2 chickens and one duck, no macroscopic or histopathological lesions were observed. Blood, liver, andgastrointestinal content samples were sent for research and identification of botulinum toxin through the serum neutralization test in mice. The presence of type C botulinum toxin was confirmed in the liver chicken of one sampled animals.Discussion: The identification of type C botulism toxin enabled the characterization of the outbreak, which is...

Surto de botulismo tipo C em aves de subsistência em Santa Catarina, Brasil / Outbreak of type C botulism in backyard poultry in Santa Catarina, Brazil

Background: Botulism is a disease caused by the ingestion of neurotoxin produced by Clostridium botulinum, characterizedby flaccid paralysis, which can lead to high mortality. They have seven types of neurotoxins (A, B, C, D, E, F, and G) and,in birds, most cases are attributed to type C. They are considered sources of botulinum toxins where the decomposition oforganic matter occurs, like stagnant water and rotting food. The main feature of the disease in birds is ascending symmetricflaccid paralysis. The present study aims to describe an outbreak of type C botulism in backyard poultry in the state ofSanta Catarina, Southern Brazil.Case: A visit was made to the property with 160 backyard poultry with a history of high mortality in the municipality ofAgrolândia, Santa Catarina. Clinical signs were characterized by paralysis of the pelvic limbs, neck and pendular wings,which progressed to death within 48 h. There was a mortality rate of 37.5% (60/160) between March and May 2019. Thesebirds were kept in an overcrowded environment, with different species (chickens, ducks, teals, and turkeys) fed irregularly.The water supplied was provided from kitchen exhaust, accumulating in puddles on the floor that contained organic matterresidues such as animal feces, food waste and bone fragments. The disposal of the carcasses of birds that died was in thesame enclosure, buried superficially, facilitating the access of other birds to dig them up and consume them. Necropsywas performed on 2 chickens and one duck, no macroscopic or histopathological lesions were observed. Blood, liver, andgastrointestinal content samples were sent for research and identification of botulinum toxin through the serum neutralization test in mice. The presence of type C botulinum toxin was confirmed in the liver chicken of one sampled animals.Discussion: The identification of type C botulism toxin enabled the characterization of the outbreak, which is...(AU)

Type C botulism in dogs from rural properties located in Goiânia, Brazil

Botulism is a disease usually fatal, caused by the ingestion of neurotoxins produced by Clostridium botulinum. In dogs, intoxication is caused by the ingestion of botulinum toxin type C, and animals often recover spontaneously. The present study describes the occurrence of type C botulism in two dogs domiciled on neighboring rural properties in the municipality of Goiânia, state of Goiás, Brazil, probably associated with ingestion of decomposing bovine carcass. Upon clinical evaluation, the dogs were alert in the lateral decubitus position with ascending flaccid paralysis, absence of eyelid reflexes, and reduced muscle tone. Due to their worsening clinical symptoms, the animals died within 12 h and 3 days after supportive treatment. Botulinum toxin type C was identified, in the serum and feces of both dogs, by seroneutralization in mice with homologous monovalent antitoxin. The results of the high-throughput gene sequencing showed that the abundance of C. botulinum in the fecal microbiota of one of the affected dogs was low (0.53%). In this way, the present study highlights the need of sanitary practices related to the appropriate collection and disposal of bovine carcasses in rural areas since they represent a risk factor for the occurrence of botulism in dogs domiciled on rural properties.

Type C botulism outbreak in free-ranging waterfowl in Goiás / Surto de botulismo tipo C em aves aquáticas de vida livre em Goiás

Botulism is generally a fatal disease caused by ingestion of neurotoxins produced by Clostridium botulinum. The present study describes the epidemiological, clinical, and laboratory aspects of a type C botulism outbreak in free-living aquatic birds residing in an urban park in Quirinópolis, Goiás, Brazil. Among a population of approximately 80 waterfowl, a total of 30 birds, including ducks (Cairina moschata), teals (Anas platyrhynchos), and geese (Anser cygnoides), died within 10 days. Of these, six birds showed signs of flaccid paralysis of the pelvic limbs, eyelids, neck, and wings. To confirm the suspicion of botulism, four lake water samples, two samples of the feed consumed by the birds, and samples of serum, intestinal content, stomach content, and liver tissue from two teals that died after presenting clinical signs were analyzed. Using bioassay and neutralization with homologous antitoxin in mice, it was possible to detect the presence of botulinum toxin type C in a water sample and in the intestinal content of one of the necropsied teals. Additionally, the presence of C. botulinum type C was identified in the lake water using polymerase chain reaction. Based on the clinical signs and laboratory results, a diagnosis of botulism caused by botulinum toxin type C was confirmed with probable transmission by lake water.

O botulismo é uma doença geralmente fatal, causada pela ingestão de neurotoxinas produzidas pelo Clostridium botulinum. O presente estudo descreve os aspectos epidemiológicos, clínicos e laboratoriais de um surto de botulismo tipo C em aves aquáticas de vida livre habitantes de parque urbano em Quirinópolis, Goiás. De uma população de cerca de 80 aves aquáticas, um total de 30 aves, entre patos (Cairina moschata), marrecos (Anas platyrhynchos) e gansos (Anser cygnoides), morreram no intervalo de 10 dias. Destes, seis aves apresentaram sinais de paralisia flácida de membros pélvicos, pálpebras, pescoço e asas. Para confirmar a suspeita de botulismo, foram analisadas quatro amostras da água do lago, duas amostras da ração consumida pelas aves e amostras de soro, conteúdo intestinal, conteúdo estomacal e fígado de dois marrecos que morreram após apresentarem os sinais clínicos. Pelo bioensaio e neutralização com antitoxina homóloga em camundongos foi possível detectar a presença de toxina botulínica tipo C em uma amostra de água e no conteúdo intestinal de um dos marrecos necropsiados. Adicionalmente, pela reação em cadeia da polimerase identificou-se a presença de C. botulinum tipo C na água do lago. Com base nos sinais clínicos e resultados laboratoriais estabeleceu-se o diagnóstico de botulismo causado pela toxina botulínica tipo C e veiculada provavelmente pela água do lago.

Exploring the five-paced viper (Deinagkistrodon acutus) venom proteome by integrating a combinatorial peptide ligand library approach with shotgun LC-MS/MS

Snake venoms are complex mixtures of toxic proteins or peptides encoded by various gene families that function synergistically to incapacitate prey. In the present study, in order to unravel the proteomic repertoire of Deinagkistrodon acutus venom, some trace abundance components were analyzed. Methods Shotgun proteomic approach combined with shotgun nano-LC-ESI-MS/MS were employed to characterize the medically important D. acutus venom, after collected samples were enriched with the combinatorial peptide ligand library (CPLL). Results This avenue helped us find some trace components, undetected before, in D. acutus venom. The results indicated that D. acutus venom comprised 84 distinct proteins from 10 toxin families and 12 other proteins. These results are more than twice the number of venom components obtained from previous studies, which were only 29 distinct proteins obtained through RP-HPLC for the venom of the same species. The present results indicated that in D. acutus venom, the most abundant components (66.9%) included metalloproteinases, serine proteinases, and C-type lectin proteins; the medium abundant components (13%) comprised phospholipases A2 (PLA2) and 5'-nucleotidases and nucleases; whereas least abundant components (6%) were aminopeptidases, L-amino acid oxidases (LAAO), neurotoxins and disintegrins; and the trace components. The last were undetected before the use of conventional shotgun proteomics combined with shotgun nano-LC-ESI-MS/MS, such as cysteine-rich secretory proteins Da-CRPa, phospholipases B-like 1, phospholipases B (PLB), nerve growth factors (NGF), glutaminyl-peptide cyclortransferases (QC), and vascular non-inflammatory molecules 2 (VNN2). Conclusion These findings demonstrated that the CPLL enrichment method worked well in finding the trace toxin proteins in D. acutus venom, in contrast with the previous venomic characterization of D. acutus by conventional LC-MS/MS. In conclusion, this approach combined with the CPLL enrichment was effective for allowing us to explore the hidden D. acutus venomic profile and extended the list of potential venom toxins.(AU)

Proteomic analysis of Red Sea Conus taeniatus venom reveals potential biological applications

Diverse and unique bioactive neurotoxins known as conopeptides or conotoxins are produced by venomous marine cone snails. Currently, these small and stable molecules are of great importance as research tools and platforms for discovering new drugs and therapeutics. Therefore, the characterization of Conus venom is of great significance, especially for poorly studied species. Methods: In this study, we used bioanalytical techniques to determine the venom profile and emphasize the functional composition of conopeptides in Conus taeniatus, a neglected worm-hunting cone snail. Results: The proteomic analysis revealed that 84.0% of the venom proteins were between 500 and 4,000 Da, and 16.0% were > 4,000 Da. In C. taeniatus venom, 234 peptide fragments were identified and classified as conotoxin precursors or non-conotoxin proteins. In this process, 153 conotoxin precursors were identified and matched to 23 conotoxin precursors and hormone superfamilies. Notably, the four conotoxin superfamilies T (22.87%), O1 (17.65%), M (13.1%) and O2 (9.8%) were the most abundant peptides in C. taeniatus venom, accounting for 63.40% of the total conotoxin diversity. On the other hand, 48 non-conotoxin proteins were identified in the venom of C. taeniatus. Moreover, several possibly biologically active peptide matches were identified, and putative applications of the peptides were assigned. Conclusion: Our study showed that the composition of the C. taeniatus-derived proteome is comparable to that of other Conus species and contains an effective mix of toxins, ionic channel inhibitors and antimicrobials. Additionally, it provides a guidepost for identifying novel conopeptides from the venom of C. taeniatus and discovering conopeptides of potential pharmaceutical importance.(AU)

Proteomic analysis of Red Sea Conus taeniatus venom reveals potential biological applications

Diverse and unique bioactive neurotoxins known as conopeptides or conotoxins are produced by venomous marine cone snails. Currently, these small and stable molecules are of great importance as research tools and platforms for discovering new drugs and therapeutics. Therefore, the characterization of Conus venom is of great significance, especially for poorly studied species. Methods: In this study, we used bioanalytical techniques to determine the venom profile and emphasize the functional composition of conopeptides in Conus taeniatus, a neglected worm-hunting cone snail. Results: The proteomic analysis revealed that 84.0% of the venom proteins were between 500 and 4,000 Da, and 16.0% were > 4,000 Da. In C. taeniatus venom, 234 peptide fragments were identified and classified as conotoxin precursors or non-conotoxin proteins. In this process, 153 conotoxin precursors were identified and matched to 23 conotoxin precursors and hormone superfamilies. Notably, the four conotoxin superfamilies T (22.87%), O1 (17.65%), M (13.1%) and O2 (9.8%) were the most abundant peptides in C. taeniatus venom, accounting for 63.40% of the total conotoxin diversity. On the other hand, 48 non-conotoxin proteins were identified in the venom of C. taeniatus. Moreover, several possibly biologically active peptide matches were identified, and putative applications of the peptides were assigned. Conclusion: Our study showed that the composition of the C. taeniatus-derived proteome is comparable to that of other Conus species and contains an effective mix of toxins, ionic channel inhibitors and antimicrobials. Additionally, it provides a guidepost for identifying novel conopeptides from the venom of C. taeniatus and discovering conopeptides of potential pharmaceutical importance.(AU)

Exploring the five-paced viper (Deinagkistrodon acutus) venom proteome by integrating a combinatorial peptide ligand library approach with shotgun LC-MS/MS

Snake venoms are complex mixtures of toxic proteins or peptides encoded by various gene families that function synergistically to incapacitate prey. In the present study, in order to unravel the proteomic repertoire of Deinagkistrodon acutus venom, some trace abundance components were analyzed. Methods Shotgun proteomic approach combined with shotgun nano-LC-ESI-MS/MS were employed to characterize the medically important D. acutus venom, after collected samples were enriched with the combinatorial peptide ligand library (CPLL). Results This avenue helped us find some trace components, undetected before, in D. acutus venom. The results indicated that D. acutus venom comprised 84 distinct proteins from 10 toxin families and 12 other proteins. These results are more than twice the number of venom components obtained from previous studies, which were only 29 distinct proteins obtained through RP-HPLC for the venom of the same species. The present results indicated that in D. acutus venom, the most abundant components (66.9%) included metalloproteinases, serine proteinases, and C-type lectin proteins; the medium abundant components (13%) comprised phospholipases A2 (PLA2) and 5'-nucleotidases and nucleases; whereas least abundant components (6%) were aminopeptidases, L-amino acid oxidases (LAAO), neurotoxins and disintegrins; and the trace components. The last were undetected before the use of conventional shotgun proteomics combined with shotgun nano-LC-ESI-MS/MS, such as cysteine-rich secretory proteins Da-CRPa, phospholipases B-like 1, phospholipases B (PLB), nerve growth factors (NGF), glutaminyl-peptide cyclortransferases (QC), and vascular non-inflammatory molecules 2 (VNN2). Conclusion These findings demonstrated that the CPLL enrichment method worked well in finding the trace toxin proteins in D. acutus venom, in contrast with the previous venomic characterization of D. acutus by conventional LC-MS/MS. In conclusion, this approach combined with the CPLL enrichment was effective for allowing us to explore the hidden D. acutus venomic profile and extended the list of potential venom toxins.(AU)

Analgesic effects of Phα1ß toxin: a review of mechanisms of action involving pain pathways

Phα1ß is a neurotoxin purified from spider venom that acts as a high-voltage-activated (HVA) calcium channel blocker. This spider peptide has shown a high selectivity for N-type HVA calcium channels (NVACC) and an analgesic effect in several animal models of pain. Its activity was associated with a reduction in calcium transients, glutamate release, and reactive oxygen species production from the spinal cord tissue and dorsal ganglia root (DRG) in rats and mice. It has been reported that intrathecal (i.t.) administration of Phα1ß to treat chronic pain reverted opioid tolerance with a safer profile than ω-conotoxin MVIIA, a highly selective NVACC blocker. Following a recent development of recombinant Phα1ß (CTK 01512-2), a new molecular target, TRPA1, the structural arrangement of disulphide bridges, and an effect on glial plasticity have been identified. CTK 01512-2 reproduced the antinociceptive effects of the native toxin not only after the intrathecal but also after the intravenous administration. Herein, we review the Phα1ß antinociceptive activity in the most relevant pain models and its mechanisms of action, highlighting the impact of CTK 01512-2 synthesis and its potential for multimodal analgesia.

Analgesic effects of Phalfa1 beta toxin: a review of mechanisms of action involving pain pathways

Phα1ß is a neurotoxin purified from spider venom that acts as a high-voltage-activated (HVA) calcium channel blocker. This spider peptide has shown a high selectivity for N-type HVA calcium channels (NVACC) and an analgesic effect in several animal models of pain. Its activity was associated with a reduction in calcium transients, glutamate release, and reactive oxygen species production from the spinal cord tissue and dorsal ganglia root (DRG) in rats and mice. It has been reported that intrathecal (i.t.) administration of Phα1ß to treat chronic pain reverted opioid tolerance with a safer profile than ω-conotoxin MVIIA, a highly selective NVACC blocker. Following a recent development of recombinant Phα1ß (CTK 01512-2), a new molecular target, TRPA1, the structural arrangement of disulphide bridges, and an effect on glial plasticity have been identified. CTK 01512-2 reproduced the antinociceptive effects of the native toxin not only after the intrathecal but also after the intravenous administration. Herein, we review the Phα1ß antinociceptive activity in the most relevant pain models and its mechanisms of action, highlighting the impact of CTK 01512-2 synthesis and its potential for multimodal analgesia.

MS/MS analysis of four scorpion venoms from Colombia: a descriptive approach

Background: Scorpions are widely known for the neurotoxic effects of their venoms, which contain peptides affecting ionic channels. Although Colombia is recognized for its scorpion diversity, only a few studies are available describing the venom content. Methods: In this descriptive study, we analyzed the MS/MS sequence, electrophoretic and chromatographic profile linked to a bioinformatics analysis of the scorpions Chactas reticulatus (Chactidae), Opisthacanthus elatus (Hormuridae), Centruroides edwardsii (Buthidae) and Tityus asthenes (Buthidae) from Colombia. Results: Each scorpion showed a specific electrophoretic and chromatographic profile. The electrophoretic profiles indicate the presence of high molecular mass compounds in all venoms, with a predominance of low molecular mass compounds in the Buthidae species. Chromatographic profiles showed a similar pattern as the electrophoretic profiles. From the MS/MS analysis of the chromatographic collected fractions, we obtained internal peptide sequences corresponding to proteins reported in scorpions from the respective family of the analyzed samples. Some of these proteins correspond to neurotoxins affecting ionic channels, antimicrobial peptides and metalloproteinase-like fragments. In the venom of Tityus asthenes, the MSn analysis allowed the detection of two toxins affecting sodium channels covering 50% and 84% of the sequence respectively, showing 100% sequence similarity. Two sequences from Tityus asthenes showed sequence similarity with a phospholipase from Opisthacanthus cayaporum indicating the presence of this type of toxin in this species for the first time. One sequence matching a hypothetical secreted protein from Hottentotta judaicus was found in three of the studied venoms. We found that this protein is common in the Buthidae family whereas it has been reported in other families - such as Scorpionidae - and may be part of the evolutionary puzzle of venoms in these arachnids. Conclusion: Buthidae venoms from Colombia can be considered an important source of peptides similar to toxins affecting ionic channels. An interesting predicted antimicrobial peptide was detected in three of the analyzed venoms.(AU)

MS/MS analysis of four scorpion venoms from Colombia: a descriptive approach

Background: Scorpions are widely known for the neurotoxic effects of their venoms, which contain peptides affecting ionic channels. Although Colombia is recognized for its scorpion diversity, only a few studies are available describing the venom content. Methods: In this descriptive study, we analyzed the MS/MS sequence, electrophoretic and chromatographic profile linked to a bioinformatics analysis of the scorpions Chactas reticulatus (Chactidae), Opisthacanthus elatus (Hormuridae), Centruroides edwardsii (Buthidae) and Tityus asthenes (Buthidae) from Colombia. Results: Each scorpion showed a specific electrophoretic and chromatographic profile. The electrophoretic profiles indicate the presence of high molecular mass compounds in all venoms, with a predominance of low molecular mass compounds in the Buthidae species. Chromatographic profiles showed a similar pattern as the electrophoretic profiles. From the MS/MS analysis of the chromatographic collected fractions, we obtained internal peptide sequences corresponding to proteins reported in scorpions from the respective family of the analyzed samples. Some of these proteins correspond to neurotoxins affecting ionic channels, antimicrobial peptides and metalloproteinase-like fragments. In the venom of Tityus asthenes, the MSn analysis allowed the detection of two toxins affecting sodium channels covering 50% and 84% of the sequence respectively, showing 100% sequence similarity. Two sequences from Tityus asthenes showed sequence similarity with a phospholipase from Opisthacanthus cayaporum indicating the presence of this type of toxin in this species for the first time. One sequence matching a hypothetical secreted protein from Hottentotta judaicus was found in three of the studied venoms. We found that this protein is common in the Buthidae family whereas it has been reported in other families - such as Scorpionidae - and may be part of the evolutionary puzzle of venoms in these arachnids. Conclusion: Buthidae venoms from Colombia can be considered an important source of peptides similar to toxins affecting ionic channels. An interesting predicted antimicrobial peptide was detected in three of the analyzed venoms.(AU)

Proteomic analysis of Red Sea Conus taeniatus venom reveals potential biological applications

Abstract Background: Diverse and unique bioactive neurotoxins known as conopeptides or conotoxins are produced by venomous marine cone snails. Currently, these small and stable molecules are of great importance as research tools and platforms for discovering new drugs and therapeutics. Therefore, the characterization of Conus venom is of great significance, especially for poorly studied species. Methods: In this study, we used bioanalytical techniques to determine the venom profile and emphasize the functional composition of conopeptides in Conus taeniatus, a neglected worm-hunting cone snail. Results: The proteomic analysis revealed that 84.0% of the venom proteins were between 500 and 4,000 Da, and 16.0% were > 4,000 Da. In C. taeniatus venom, 234 peptide fragments were identified and classified as conotoxin precursors or non-conotoxin proteins. In this process, 153 conotoxin precursors were identified and matched to 23 conotoxin precursors and hormone superfamilies. Notably, the four conotoxin superfamilies T (22.87%), O1 (17.65%), M (13.1%) and O2 (9.8%) were the most abundant peptides in C. taeniatus venom, accounting for 63.40% of the total conotoxin diversity. On the other hand, 48 non-conotoxin proteins were identified in the venom of C. taeniatus. Moreover, several possibly biologically active peptide matches were identified, and putative applications of the peptides were assigned. Conclusion: Our study showed that the composition of the C. taeniatus-derived proteome is comparable to that of other Conus species and contains an effective mix of toxins, ionic channel inhibitors and antimicrobials. Additionally, it provides a guidepost for identifying novel conopeptides from the venom of C. taeniatus and discovering conopeptides of potential pharmaceutical importance.

Exploring the five-paced viper (Deinagkistrodon acutus) venom proteome by integrating a combinatorial peptide ligand library approach with shotgun LC-MS/MS

Abstract Background Snake venoms are complex mixtures of toxic proteins or peptides encoded by various gene families that function synergistically to incapacitate prey. In the present study, in order to unravel the proteomic repertoire of Deinagkistrodon acutus venom, some trace abundance components were analyzed. Methods Shotgun proteomic approach combined with shotgun nano-LC-ESI-MS/MS were employed to characterize the medically important D. acutus venom, after collected samples were enriched with the combinatorial peptide ligand library (CPLL). Results This avenue helped us find some trace components, undetected before, in D. acutus venom. The results indicated that D. acutus venom comprised 84 distinct proteins from 10 toxin families and 12 other proteins. These results are more than twice the number of venom components obtained from previous studies, which were only 29 distinct proteins obtained through RP-HPLC for the venom of the same species. The present results indicated that in D. acutus venom, the most abundant components (66.9%) included metalloproteinases, serine proteinases, and C-type lectin proteins; the medium abundant components (13%) comprised phospholipases A2 (PLA2) and 5-nucleotidases and nucleases; whereas least abundant components (6%) were aminopeptidases, L-amino acid oxidases (LAAO), neurotoxins and disintegrins; and the trace components. The last were undetected before the use of conventional shotgun proteomics combined with shotgun nano-LC-ESI-MS/MS, such as cysteine-rich secretory proteins Da-CRPa, phospholipases B-like 1, phospholipases B (PLB), nerve growth factors (NGF), glutaminyl-peptide cyclortransferases (QC), and vascular non-inflammatory molecules 2 (VNN2). Conclusion These findings demonstrated that the CPLL enrichment method worked well in finding the trace toxin proteins in D. acutus venom, in contrast with the previous venomic characterization of D. acutus by conventional LC-MS/MS. In conclusion, this approach combined with the CPLL enrichment was effective for allowing us to explore the hidden D. acutus venomic profile and extended the list of potential venom toxins.

De novo venom gland transcriptomics of Calliophis bivirgata flaviceps: uncovering the complexity of toxins from the Malayan blue coral snake

The Malayan blue coral snake, Calliophis bivirgata flaviceps, is a medically important venomous snake in Southeast Asia. However, the complexity and diversity of its venom genes remain little explored. Methods: To address this, we applied high-throughput next-generation sequencing to profile the venom gland cDNA libraries of C. bivirgata flaviceps. The transcriptome was de novo assembled, followed by gene annotation, multiple sequence alignment and analyses of the transcripts. Results: A total of 74 non-redundant toxin-encoding genes from 16 protein families were identified, with 31 full-length toxin transcripts. Three-finger toxins (3FTx), primarily delta-neurotoxins and cardiotoxin-like/cytotoxin-like proteins, were the most diverse and abundantly expressed. The major 3FTx (Cb_FTX01 and Cb_FTX02) are highly similar to calliotoxin, a delta-neurotoxin previously reported in the venom of C. bivirgata. This study also revealed a conserved tyrosine residue at position 4 of the cardiotoxin-like/cytotoxin-like protein genes in the species. These variants, proposed as Y-type CTX-like proteins, are similar to the H-type CTX from cobras. The substitution is conservative though, preserving a less toxic form of elapid CTX-like protein, as indicated by the lack of venom cytotoxicity in previous laboratory and clinical findings. The ecological role of these toxins, however, remains unclear. The study also uncovered unique transcripts that belong to phospholipase A2 of Groups IA and IB, and snake venom metalloproteinases of PIII subclass, which show sequence variations from those of Asiatic elapids. Conclusion: The venom gland transcriptome of C. bivirgata flaviceps from Malaysia was de novo assembled and annotated. The diversity and expression profile of toxin genes provide insights into the biological and medical importance of the species.(AU)

De novo venom gland transcriptomics of Calliophis bivirgata flaviceps: uncovering the complexity of toxins from the Malayan blue coral snake

The Malayan blue coral snake, Calliophis bivirgata flaviceps, is a medically important venomous snake in Southeast Asia. However, the complexity and diversity of its venom genes remain little explored. Methods: To address this, we applied high-throughput next-generation sequencing to profile the venom gland cDNA libraries of C. bivirgata flaviceps. The transcriptome was de novo assembled, followed by gene annotation, multiple sequence alignment and analyses of the transcripts. Results: A total of 74 non-redundant toxin-encoding genes from 16 protein families were identified, with 31 full-length toxin transcripts. Three-finger toxins (3FTx), primarily delta-neurotoxins and cardiotoxin-like/cytotoxin-like proteins, were the most diverse and abundantly expressed. The major 3FTx (Cb_FTX01 and Cb_FTX02) are highly similar to calliotoxin, a delta-neurotoxin previously reported in the venom of C. bivirgata. This study also revealed a conserved tyrosine residue at position 4 of the cardiotoxin-like/cytotoxin-like protein genes in the species. These variants, proposed as Y-type CTX-like proteins, are similar to the H-type CTX from cobras. The substitution is conservative though, preserving a less toxic form of elapid CTX-like protein, as indicated by the lack of venom cytotoxicity in previous laboratory and clinical findings. The ecological role of these toxins, however, remains unclear. The study also uncovered unique transcripts that belong to phospholipase A2 of Groups IA and IB, and snake venom metalloproteinases of PIII subclass, which show sequence variations from those of Asiatic elapids. Conclusion: The venom gland transcriptome of C. bivirgata flaviceps from Malaysia was de novo assembled and annotated. The diversity and expression profile of toxin genes provide insights into the biological and medical importance of the species.(AU)

Tratamento de tétano em égua gestante / Tetanus treatmentin pregnant mare / Tratamiento contra el tétanos em yegua preñada

O tétano é uma doença infecciosa não contagiosa, desencadeada pela ação de neurotoxinas produzidas pela bactéria Clostridium tetani. Dentre as espécies mais suscetíveis e de maior ocorrência em estudos epidemiológicos, destacam-se os equinos. Neste estudo de caso, foi atendido no Hospital Veterinário do IFPB campus Sousa, uma fêmea equina, SRD, 8 anos de idade, no 6º mês de gestação. O animal apresentava taquipneia, taquicardia, espasticidade dos membros, protrusão da terceira pálpebra, hiperestesia, cauda em bandeira, rigidez da musculatura do abdome e discreta rigidez da musculatura cervical. Com a intervenção medicamentosa baseada no uso de soro antitetânico, antibioticoterapia com benzilpenicilina benzatina, acepromazina e fluidoterapia à base de solução de ringer com lactato, associado ao repouso em ambiente silencioso e termicamente agradável, obteve-se resultados satisfatórios nos primeiros dias do inicio do tratamento e recuperação total após o 15º dia. Além disso, ao 15°dia pós-internamento e antecedendo a alta do animal foi realizada a avaliação ultrassonográfica transretal, confirmando a viabilidade fetal.

Tetanus is a non-contagious infectious disease triggered by neurotoxins produced by the bacterium Clostridium tetani. Horses are among the most susceptible species and also are frequent targets in epidemiological studies. In this case study, a mare, crossbred, 8 years old, in the sixth month of gestation, was assisted at the Veterinary Hospital at IFPB Sousa campus. The animal was presenting some clinical signs, such as tachypnea, tachycardia, limb spasticity, protrusion of the third eyelid, hyperesthesia, elevated tail, stiffness of the abdomen muscles and slight stiffness of the cervical muscles. Medicines treatment was based on the use of tetanus antitoxin, benzathine penicillin antibiotic therapy, acepromazine and lactate ringer's solution therapy, combined with a calm and thermally pleasant environment. Satisfactory results were obtained from the first days of treatment and full recovery of the animal after the 15th day of hospitalization. In addition, on the 15thday after admission at the hospital and before discharge, a transrectal ultrasound evaluation was performed, confirming fetal viability.

El tétano es uma enfermedad infecciosa desencadenada por la acción de las neurotoxinas producidas por la bacteria Clostridium tetani. Entre las especies más susceptibles y más frecuentes en estudios epidemiológicos, destacan los caballos. En este estudio de caso, fue vista en el Hospital Veterinario Campus Sousa de IFPB, una yegua preñada, SRD, de 8 años de edad, en el sexto mes degestación. El animal presentaba taquipnea, taquicardia, espasticidad, posición del caballete, protrusión del tercer párpado, hiperestesia, colade bandera, rigidez de los músculos del abdomen y leve rigidez de los músculos cervicales. Con la intervención farmacológica basada en el uso del suero antitetánico, la terapia con antibióticos benzatínicos y bencilpenicilinas, la acepromacina y la fluidoterapia basada en la solución de Ringer lactato, asociada con un descanso tranquilo y placentero térmicamente, se obtuvieron resultados satisfactorios en los primeros días de inicio del tratamiento. y recuperación completa después del día 15. Además, el día 15 después del ingreso y antes del alta del animal, se realizó una evaluación ecográfica transrectal, confirmando la viabilidad fetal.

Tratamento de tétano em égua gestante / Tetanus treatmentin pregnant mare / Tratamiento contra el tétanos em yegua preñada

O tétano é uma doença infecciosa não contagiosa, desencadeada pela ação de neurotoxinas produzidas pela bactéria Clostridium tetani. Dentre as espécies mais suscetíveis e de maior ocorrência em estudos epidemiológicos, destacam-se os equinos. Neste estudo de caso, foi atendido no Hospital Veterinário do IFPB campus Sousa, uma fêmea equina, SRD, 8 anos de idade, no 6º mês de gestação. O animal apresentava taquipneia, taquicardia, espasticidade dos membros, protrusão da terceira pálpebra, hiperestesia, cauda em bandeira, rigidez da musculatura do abdome e discreta rigidez da musculatura cervical. Com a intervenção medicamentosa baseada no uso de soro antitetânico, antibioticoterapia com benzilpenicilina benzatina, acepromazina e fluidoterapia à base de solução de ringer com lactato, associado ao repouso em ambiente silencioso e termicamente agradável, obteve-se resultados satisfatórios nos primeiros dias do inicio do tratamento e recuperação total após o 15º dia. Além disso, ao 15°dia pós-internamento e antecedendo a alta do animal foi realizada a avaliação ultrassonográfica transretal, confirmando a viabilidade fetal.(AU)

Tetanus is a non-contagious infectious disease triggered by neurotoxins produced by the bacterium Clostridium tetani. Horses are among the most susceptible species and also are frequent targets in epidemiological studies. In this case study, a mare, crossbred, 8 years old, in the sixth month of gestation, was assisted at the Veterinary Hospital at IFPB Sousa campus. The animal was presenting some clinical signs, such as tachypnea, tachycardia, limb spasticity, protrusion of the third eyelid, hyperesthesia, elevated tail, stiffness of the abdomen muscles and slight stiffness of the cervical muscles. Medicines treatment was based on the use of tetanus antitoxin, benzathine penicillin antibiotic therapy, acepromazine and lactate ringer's solution therapy, combined with a calm and thermally pleasant environment. Satisfactory results were obtained from the first days of treatment and full recovery of the animal after the 15th day of hospitalization. In addition, on the 15thday after admission at the hospital and before discharge, a transrectal ultrasound evaluation was performed, confirming fetal viability.(AU)

El tétano es uma enfermedad infecciosa desencadenada por la acción de las neurotoxinas producidas por la bacteria Clostridium tetani. Entre las especies más susceptibles y más frecuentes en estudios epidemiológicos, destacan los caballos. En este estudio de caso, fue vista en el Hospital Veterinario Campus Sousa de IFPB, una yegua preñada, SRD, de 8 años de edad, en el sexto mes degestación. El animal presentaba taquipnea, taquicardia, espasticidad, posición del caballete, protrusión del tercer párpado, hiperestesia, colade bandera, rigidez de los músculos del abdomen y leve rigidez de los músculos cervicales. Con la intervención farmacológica basada en el uso del suero antitetánico, la terapia con antibióticos benzatínicos y bencilpenicilinas, la acepromacina y la fluidoterapia basada en la solución de Ringer lactato, asociada con un descanso tranquilo y placentero térmicamente, se obtuvieron resultados satisfactorios en los primeros días de inicio del tratamiento. y recuperación completa después del día 15. Además, el día 15 después del ingreso y antes del alta del animal, se realizó una evaluación ecográfica transrectal, confirmando la viabilidad fetal.(AU)