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  1 / 1144 MEDLINE  
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PMID:29235805
Autor:Rader MD
Título:Buying Snake Heads.
Fonte:J Indiana Dent Assoc; 95(3):47, 2016.
ISSN:0019-6568
País de publicação:United States
Idioma:eng
Tipo de publicação: JOURNAL ARTICLE


  2 / 1144 MEDLINE  
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PMID:28749688
Autor:Dubovskii PV; Dubinnyi MA; Konshina AG; Kazakova ED; Sorokoumova GM; Ilyasova TM; Shulepko MA; Chertkova RV; Lyukmanova EN; Dolgikh DA; Arseniev AS; Efremov RG
Endereço:Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences , 16/10 Miklukho-Maklaya str., Moscow 117997, Russia.
Título:Structural and Dynamic "Portraits" of Recombinant and Native Cytotoxin I from Naja oxiana: How Close Are They?
Fonte:Biochemistry; 56(34):4468-4477, 2017 08 29.
ISSN:1520-4995
País de publicação:United States
Idioma:eng
Resumo:Today, recombinant proteins are quite widely used in biomedical and biotechnological applications. At the same time, the question about their full equivalence to the native analogues remains unanswered. To gain additional insight into this problem, intimate atomistic details of a relatively simple protein, small and structurally rigid recombinant cardiotoxin I (CTI) from cobra Naja oxiana venom, were characterized using nuclear magnetic resonance (NMR) spectroscopy and atomistic molecular dynamics (MD) simulations in water. Compared to the natural protein, it contains an additional Met residue at the N-terminus. In this work, the NMR-derived spatial structure of uniformly C- and N-labeled CTI and its dynamic behavior were investigated and subjected to comparative analysis with the corresponding data for the native toxin. The differences were found in dihedral angles of only a single residue, adjacent to the N-terminal methionine. Microsecond-long MD traces of the toxins reveal an increased flexibility in the residues spatially close to the N-Met. As the detected structural and dynamic changes of the two CTI models do not result in substantial differences in their cytotoxicities, we assume that the recombinant protein can be used for many purposes as a reasonable surrogate of the native one. In addition, we discuss general features of the spatial organization of cytotoxins, implied by the results of the current combined NMR and MD study.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
Nome de substância:0 (Elapid Venoms); 0 (Recombinant Proteins); 0 (cobra cytotoxin I)


  3 / 1144 MEDLINE  
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PMID:28700055
Autor:Oliveira FDR; Noronha MDDN; Lozano JLL
Endereço:Laboratório de Ecologia e Biotecnologia de Microrganismos da Amazônia, Instituto Nacional de Pesquisas da Amazônia , Manaus, AM, Brasil.
Título:Biological and molecular properties of yellow venom of the Amazonian coral snake Micrurus surinamensis.
Fonte:Rev Soc Bras Med Trop; 50(3):365-373, 2017 May-Jun.
ISSN:1678-9849
País de publicação:Brazil
Idioma:eng
Resumo:INTRODUCTION:: The coral snake Micrurus surinamensis, which is widely distributed throughout Amazonia, has a neurotoxic venom. It is important to characterize the biological and molecular properties of this venom in order to develop effective antitoxins. METHODS:: Toxins from the venom of M. surinamensis were analyzed by two-dimensional polyacrylamide gel electrophoresis and their neurotoxic effects in vivo were evaluated. RESULTS AND CONCLUSIONS:: Most proteins in the venom had masses < 14kDa, low phospholipase A2 activity, and no proteolytic activity. The toxins inhibited the coagulation cascade. The venom had neurotoxic effects in mice, with a median lethal dose upon intravenous administration of 700 µg/kg. Immunogenic studies revealed abundant cross-reactivity of antielapidic serum with 14kDa toxins and limited cross-reactivity with toxins < 10kDa. These results indicate that antielapidic serum against M. surinamensis venom has weak potency (0.35mg/ml) in mice.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Elapid Venoms); EC 3.1.1.4 (Phospholipases A2)


  4 / 1144 MEDLINE  
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PMID:28552595
Autor:Zhang Y; Zhu W; Deng XY; Peng JM; Li CM
Endereço:College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Título:Both non-covalent and covalent interactions were involved in the mechanism of detoxifying effects of persimmon tannin on Chinese cobra PLA .
Fonte:Fitoterapia; 120:41-51, 2017 Jul.
ISSN:1873-6971
País de publicação:Netherlands
Idioma:eng
Resumo:Persimmon tannin (PT) has been shown to inhibit snake venom activities and toxicities both in vitro and in vivo. To clarify the detoxifying mechanism of PT on snake venom, the interaction of characteristic structural elements of PT (EGCG, ECG, EGCG dimer and ECG dimer) and Chinese cobra phospholipase A (PLA ) was studied. The results revealed that except non-covalent bonds like hydrogen bonds, hydrophobic bonds and iron bonds were formed between PT and PLA , covalent interaction was also occurred. PT could bind with the key active residues of PLA , such as lysine, histidine, tryptophan and tyrosine, restraining their activity and disturbing the structure of PLA , thus showing detoxifying effects on snake venom.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Snake Venoms); EC 3.1.1.4 (Phospholipases A2)


  5 / 1144 MEDLINE  
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PMID:28335411
Autor:Panagides N; Jackson TN; Ikonomopoulou MP; Arbuckle K; Pretzler R; Yang DC; Ali SA; Koludarov I; Dobson J; Sanker B; Asselin A; Santana RC; Hendrikx I; van der Ploeg H; Tai-A-Pin J; van den Bergh R; Kerkkamp HM; Vonk FJ; Naude A; Strydom MA; Jacobsz L; Dunstan N; Jaeger M; Hodgson WC; Miles J; Fry BG
Endereço:Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia. nadya.panagides@gmail.com.
Título:How the Cobra Got Its Flesh-Eating Venom: Cytotoxicity as a Defensive Innovation and Its Co-Evolution with Hooding, Aposematic Marking, and Spitting.
Fonte:Toxins (Basel); 9(3), 2017 Mar 13.
ISSN:2072-6651
País de publicação:Switzerland
Idioma:eng
Resumo:The cytotoxicity of the venom of 25 species of Old World elapid snake was tested and compared with the morphological and behavioural adaptations of hooding and spitting. We determined that, contrary to previous assumptions, the venoms of spitting species are not consistently more cytotoxic than those of closely related non-spitting species. While this correlation between spitting and non-spitting was found among African cobras, it was not present among Asian cobras. On the other hand, a consistent positive correlation was observed between cytotoxicity and utilisation of the defensive hooding display that cobras are famous for. Hooding and spitting are widely regarded as defensive adaptations, but it has hitherto been uncertain whether cytotoxicity serves a defensive purpose or is somehow useful in prey subjugation. The results of this study suggest that cytotoxicity evolved primarily as a defensive innovation and that it has co-evolved twice alongside hooding behavior: once in the and again independently in the king cobras ( ). There was a significant increase of cytotoxicity in the Asian linked to the evolution of bold aposematic hood markings, reinforcing the link between hooding and the evolution of defensive cytotoxic venoms. In parallel, lineages with increased cytotoxicity but lacking bold hood patterns evolved aposematic markers in the form of high contrast body banding. The results also indicate that, secondary to the evolution of venom rich in cytotoxins, spitting has evolved three times independently: once within the African , once within the Asian , and once in the genus. The evolution of cytotoxic venom thus appears to facilitate the evolution of defensive spitting behaviour. In contrast, a secondary loss of cytotoxicity and reduction of the hood occurred in the water cobra , which possesses streamlined neurotoxic venom similar to that of other aquatic elapid snakes (e.g., hydrophiine sea snakes). The results of this study make an important contribution to our growing understanding of the selection pressures shaping the evolution of snake venom and its constituent toxins. The data also aid in elucidating the relationship between these selection pressures and the medical impact of human snakebite in the developing world, as cytotoxic cobras cause considerable morbidity including loss-of-function injuries that result in economic and social burdens in the tropics of Asia and sub-Saharan Africa.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Elapid Venoms); 0 (Neurotoxins)


  6 / 1144 MEDLINE  
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PMID:28315380
Autor:Rey-Suárez P; Núñez V; Saldarriaga-Córdoba M; Lomonte B
Endereço:Programa de Ofidismo y Escorpionismo, Universidad de Antioquia, Medellín, Colombia. Electronic address: ofidpa@gmail.com.
Título:Primary structures and partial toxicological characterization of two phospholipases A from Micrurus mipartitus and Micrurus dumerilii coral snake venoms.
Fonte:Biochimie; 137:88-98, 2017 Jun.
ISSN:1638-6183
País de publicação:France
Idioma:eng
Resumo:Snake venom phospholipases A (PLA ) share high sequence identities and a conserved structural scaffold, but show important functional differences. Only a few PLA s have been purified and characterized from coral snake (Micrurus spp.) venoms, and their role in envenomation remains largely unknown. In this report, we describe the isolation, sequencing and partial functional characterization of two Micrurus PLA s: MmipPLA from Micrurus mipartitus and MdumPLA from Micrurus dumerilii, two species of clinical importance in Colombia. MmipPLA consisted of 119 amino acid residues with a predicted pI of 8.4, whereas MdumPLA consisted of 117 residues with a pI of 5.6. Both PLA s showed the conserved 'group I' cysteine pattern and were enzymatically active, although MdumPLA had higher activity. The two enzymes differed notably in their toxicity, with MmipPLA being highly lethal to mice and mildly myotoxic, whereas MdumPLA was not lethal (up to 3 µg/g body weight) but strongly myotoxic. MdumPLA displayed higher anticoagulant activity than MmipPLA in vitro and caused more sustained edema in the mouse footpad assay. Neither of these enzymes was cytolytic to cultured skeletal muscle C2C12 myotubes. Based on their structural differences, the two enzymes were placed in separate lineages in a partial phylogeny of Micrurus venom PLA s and this classification agreed with their divergent biological activities. Overall, these findings highlight the structural and functional diversity of Micrurus venom PLA s.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Anticoagulants); 0 (Elapid Venoms); EC 3.1.1.4 (Phospholipases A2)


  7 / 1144 MEDLINE  
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PMID:28284847
Autor:Torres-Bonilla KA; Floriano RS; Schezaro-Ramos R; Rodrigues-Simioni L; da Cruz-Höfling MA
Endereço:Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, 13083-862 Campinas, SP, Brazil; Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), R
Título:A survey on some biochemical and pharmacological activities of venom from two Colombian colubrid snakes, Erythrolamprus bizona (Double-banded coral snake mimic) and Pseudoboa neuwiedii (Neuwied's false boa).
Fonte:Toxicon; 131:29-36, 2017 Jun 01.
ISSN:1879-3150
País de publicação:England
Idioma:eng
Resumo:Colombian colubrid snake venoms have been poorly studied. They represent a great resource of biological, ecological, toxinological and pharmacological research. We assessed some enzymatic properties and neuromuscular effects of Erythrolamprus bizona and Pseudoboa neuwiedii venoms from Colombia. Proteolytic, amidolytic and phospholipase A (PLA ) activities were analyzed using colorimetric assays and the neuromuscular activity was analyzed in chick biventer cervicis (BC) preparations. The venom of both species showed very low PLA and amidolytic activities; however, both exhibited high proteolytic activity, which in E. bizona venom surpassed that of P. neuwiedii venom. E. bizona and P. neuwiedii venoms provoked partial neuromuscular blockade, which was more prominent in P. neuwiedii venom. E. bizona venom (30 µg/ml) induced a significant potentiation of the contracture response to exogenous ACh (110 µM), which was not accompanied by twitch height alteration, whereas the highest venom concentration (100 µg/ml) inhibited contracture responses to both ACh and KCl (40 mM). In contrast, P. neuwiedii venom (30 and 100 µg/ml) caused significant reduction in the contracture responses to exogenous ACh and KCl. The morphological analyses showed high myotoxic effects in the muscle fibers of BC incubated with either venoms; however, they are more prominent in the P. neuwiedii venom. Our results suggest that the myotoxicity of the venom of the two Colombian species can be ascribed to their high proteolytic activity. An interesting data was the potentiation of the ACh-induced contracture, but not the twitch height, caused by E. bizona venom, at a concentration that is harmless to muscle fibers integrity. This phenomenon remains to be further elucidated, and suggest that a possible involvement of post-synaptic receptors cannot be discarded. This work is a contribution to expand the knowledge on colubrid venoms; it allows envisaging that the two venoms offer the potential to go further in the identification of their components and biological targets.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Neuromuscular Blocking Agents); 0 (Snake Venoms); EC 3.1.1.4 (Phospholipases A2)


  8 / 1144 MEDLINE  
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PMID:28209480
Autor:Anderson GP; Liu JH; Zabetakis D; Liu JL; Goldman ER
Endereço:US Naval Research Laboratory, Center for Biomolecular Science and Engineering, 4555 Overlook Ave SW, Washington, DC, 20375, USA. Electronic address: george.anderson@nrl.navy.mil.
Título:Thermal stabilization of anti-α-cobratoxin single domain antibodies.
Fonte:Toxicon; 129:68-73, 2017 Apr.
ISSN:1879-3150
País de publicação:England
Idioma:eng
Resumo:There is an unmet need for snake antivenoms that can be stored ready to use near the point of care. To address that need we have taken two anti-α-cobratoxin single domain antibodies and increased their thermal stability to improve their ambient temperature shelf-life. The anti-α-cobratoxin single domain antibodies C2 and C20 were first isolated, and demonstrated to be toxin neutralizing by Richard et al., 2013 (Richard, G., Meyers, A.J., McLean, M.D., Arbabi-Ghahroudi, M., MacKenzie, R., Hall, J.C., 2013. In vivo neutralization of alpha-cobratoxin with high-affinity llama single-domain antibodies (VHHs) and a VHH-Fc antibody. PLoS One 8, e69495). To thermal stabilize C2 and C20, we first made changes to their frame work 1 region that we had previously identified to be stabilizing, as well as reverted to the hallmark amino acids highly conserved in VHH domains; these changes improved their melting temperature (Tm) by 2 and 6 °C respectively. The further addition of a non-canonical disulfide bond raised the Tm an additional 13 and 9 °C respectively; giving final Tm values of 86 and 75 °C. Testing these mutants at 1 mg/mL at a range of elevated temperatures for an hour; we found that at 65 °C the wild type C2 and C20 had lost 35 and 95% of their binding activity respectively, while the mutants with the added disulfide bond retained nearly 100% of their initial binding activity. While significant work remains to formulate and field a shelf-stable antivenom, our results indicate such a product should be attainable in the near future.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antivenins); 0 (Cobra Neurotoxin Proteins); 0 (Single-Domain Antibodies); 69344-74-7 (alpha-cobratoxin)


  9 / 1144 MEDLINE  
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PMID:28138054
Autor:Faiz MA; Ahsan MF; Ghose A; Rahman MR; Amin R; Hossain M; Tareq MNU; Jalil MA; Kuch U; Theakston RDG; Warrell DA; Harris JB
Endereço:Dev Care Foundation, Dhaka, Bangladesh.
Título:Bites by the Monocled Cobra, , in Chittagong Division, Bangladesh: Epidemiology, Clinical Features of Envenoming and Management of 70 Identified Cases.
Fonte:Am J Trop Med Hyg; 96(4):876-884, 2017 Apr.
ISSN:1476-1645
País de publicação:United States
Idioma:eng
Resumo:AbstractWe describe 70 cases of monocled cobra ( ) bite admitted to Chittagong Medical College Hospital, Bangladesh. The biting snakes were identified by examining the dead snake and/or detecting venom antigens in patients' serum. Bites were most common in the early morning and evening during the monsoon (May-July). Ligatures were routinely applied to the bitten limb before admission. Thirty-seven patients consulted traditional healers, most of whom made incisions around the bite site. Fifty-eight patients experienced severe neurotoxicity and most suffered swelling and pain of the bitten limb. The use of an Indian polyvalent antivenom in patients exhibiting severe neurotoxicity resulted in clinical improvement but most patients experienced moderate-to-severe adverse reactions. Antivenom did not influence local blistering and necrosis appearing in 19 patients; 12 required debridement. Edrophonium significantly improved the ability of patients to open the eyes, endurance of upward gaze, and peak expiratory flow rate suggesting that a longer-acting anticholinesterase drug (neostigmine) could be recommended for first aid. The study suggested that regionally appropriate antivenom should be raised against the venoms of the major envenoming species of Bangladesh and highlighted the need to improve the training of staff of local medical centers and to invest in the basic health infrastructure in rural communities.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antivenins); 0 (Elapid Venoms); 0 (Naja kaouthia venom); 70FP3JLY7N (Edrophonium)


  10 / 1144 MEDLINE  
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PMID:28067855
Autor:Shi YJ; Chen YJ; Hu WP; Chang LS
Endereço:Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. a786514@gmail.com.
Título:Detection of Naja atra Cardiotoxin Using Adenosine-Based Molecular Beacon.
Fonte:Toxins (Basel); 9(1), 2017 Jan 07.
ISSN:2072-6651
País de publicação:Switzerland
Idioma:eng
Resumo:This study presents an adenosine (A)-based molecular beacon (MB) for selective detection of cardiotoxin (CTX) that functions by utilizing the competitive binding between CTX and the poly(A) stem of MB to coralyne. The 5'- and 3'-end of MB were labeled with a reporter fluorophore and a non-fluorescent quencher, respectively. Coralyne induced formation of the stem-loop MB structure through A2-coralyne-A2 coordination, causing fluorescence signal turn-off due to fluorescence resonance energy transfer between the fluorophore and quencher. CTX3 could bind to coralyne. Moreover, CTX3 alone induced the folding of MB structure and quenching of MB fluorescence. Unlike that of snake venom α-neurotoxins, the fluorescence signal of coralyne-MB complexes produced a bell-shaped concentration-dependent curve in the presence of CTX3 and CTX isotoxins; a turn-on fluorescence signal was noted when CTX concentration was ≤80 nM, while a turn-off fluorescence signal was noted with a further increase in toxin concentrations. The fluorescence signal of coralyne-MB complexes yielded a bell-shaped curve in response to varying concentrations of crude venom but not those of and venoms. Moreover, venom also functioned as venom to yield a bell-shaped concentration-dependent curve of MB fluorescence signal, again supporting that the hairpin-shaped MB could detect crude venoms containing CTXs. Taken together, our data validate that a platform composed of coralyne-induced stem-loop MB structure selectively detects CTXs.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Berberine Alkaloids); 0 (Cobra Cardiotoxin Proteins); 0 (Polymers); 30143-02-3 (polyadenosine); 6872-73-7 (coralyne); K72T3FS567 (Adenosine)



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