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Lourival D Possani - One of the best experts on this subject based on the ideXlab platform.
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Putative calcium channel specific toxins found in U. yaschenkoi transcriptome.
2015Co-Authors: Karen Luna-ramírez, Verónica Quintero-hernández, Víctor Rivelino Juárez-gonzález, Lourival D PossaniAbstract:Three different multiple alignments of sequences are shown that code for: (A) calcins. Comp749_c0_seq1 codes for a calcin of 33 amino acid similar to other scorpion calcins as Hadrucalcin (UniProtKB/Swiss-Prot: B8QG00.1) from Hadrurus gertschi, Imperatoxin-A (UniProtKB/Swiss-Prot: P59868.1) from Pandinus imperator, Maurocalcin (UniProtKB/Swiss-Prot: P60254.1) from Scorpio maurus palmatus and Opicalcin-1 (UniProtKB/Swiss-Prot: P60252.1) from Opistophthalmus carinatus. All of them have 6 conserved cysteine; (B) LaIT1-like calcins. Sequence comp10032_c0_seq1 of U. yaschenkoi is compared with DDH-Uro-1 (GenBank: GALI01000015.1), DDH-Uro-2 (GenBank: GALI01000016.1) and DDH-Uro-3 (GenBank: GALI01000017.1) from U. manicatus, Insecticidal toxin LaIT1 from Liocheles australasiae (UniProtKB/Swiss-Prot: P0C5F2.1) and Phi-liotoxin-Lw1a (UniProtKB/Swiss-Prot: P0DJ08.1) from Liocheles waigiensis. This class of calcins has four cysteines. The sequence reported for DDH-Uro-3 contains undefined nucleotides and therefore the XX undefined amino acids. Finally, (C) Omega Agatoxin-like calcins. Putative calcium channel specific toxins encoded by sequences Comp27527_c0_seq1 and comp104104_c0_seq1 from U. yaschenkoi are shown and compared with DAPPUDRAFT_310236 of Daphnia pulex, LOC100163563 of insect Acyrthosiphon pisum and Omega Agatoxin IVB (Omega-Aga-IVB; GenBank: P37045) of spider Agelenopsis aperta. This class of calcin has eight cysteines. The percentage of identity (% Identity) is shown for all alignments with respect to the first sequence of each alignment. Conserved cysteines and amino acids are highlighted in yellow and bold, respectively.
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Putative toxin sequences derived from the precursors found in the Vaejovis libraries.
2015Co-Authors: Verónica Quintero-hernández, Lourival D Possani, Santos Ramírez-carreto, María Teresa Romero-gutiérrez, Laura L. Valdez-velázquez, Baltazar Becerril, Ernesto OrtizAbstract:The peptide length (aa) always refers to the confirmed (when the peptide has been isolated from the venom) or software-predicted mature peptides. The identity (%I) is always relative to the first sequence of the alignment, and considers only the mature peptide regions. When present, the signal peptides are shown underlined and the propeptides are in italics and bold. The conserved cysteine arrangement typical of each family is highlighted. A) Sequence alignment of the putative sodium channel toxins. The precursor sequences of ViNaTx1 from V. intrepidus, VpNaTx1 and VpNaTx2 from V. punctatus, VsNaTx1 and VsNaTx2 from V. subcristatus, and VmNaTx1 from V. mexicanus are compared to the known sodium channel-specific ß-toxins Birtoxin (UniProt:P58752), Ikitoxin (UniProt:P0C1B8) and Altitoxin (UniProt:P0C1B5) from Parabuthus transvaalicus. B) Comparative alignments of the sequences found that belong to the two families of potassium channel-specific α-toxins. First, the precursor sequences of the six-cysteines α-toxins ViKTx1 form V. intrepidus and VpKTx4 from V. punctatus aligned to KTX-2 (Kaliotoxin-2, UniProt:P45696) from Androctonus australis and TdK1 (UniProt:P59925) from Tityus discrepans as references. Second, the precursor sequences coding for the toxins belonging to the family of the eight-cysteines α-toxins VmKTx1 from V. mexicanus and VpKTx3 from V. punctatus, aligned to Vm24 (UniProt:P0DJ31) from V. mexicanus and HgeTx1 (UniProt:P84864) from Hadrurus gertschi as references. C) The precursor sequence of VmKTx2 from V. mexicanus compared to the precursor sequence of HelaTx1 (UniProt:P0DJ41) from Heterometrus laoticus and κ-HfTx1 (UniProt:P82850) plus κ-HfTx2 (UniProt:P82851) from Heterometrus fulvipes, all belonging to the family of potassium channel-specific κ-toxins. D) The scorpine-like sequences ViScplp1–3 from V. intrepidus, VmScplp1–3 from V. mexicanus, VpScplp1 from V. punctatus, and the partial sequences of VsScplp1–2 from V. subcristatus are aligned. For comparison, the sequences of scorpine (UniProt:P56972) from P. imperator, HgeScplp1 (UniProt:Q0GY40) and HgeScplp2 (UniProt:P0C8W5) from H. gertschi are also included in the alignment.
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characterization of the venom from the australian scorpion urodacus yaschenkoi molecular mass analysis of components cdna sequences and peptides with antimicrobial activity
Toxicon, 2013Co-Authors: Karen Lunaramirez, Veronica Quinterohernandez, Leonel Vargasjaimes, Cesar Vicente Ferreira Batista, Kenneth D Winkel, Lourival D PossaniAbstract:The Urodacidae scorpions are the most widely distributed of the four families in Australia and represent half of the species in the continent, yet their venoms remain largely unstudied. This communication reports the first results of a proteome analysis of the venom of the scorpion Urodacus yaschenkoi performed by mass fingerprinting, after high performance liquid chromatography (HPLC) separation. A total of 74 fractions were obtained by HPLC separation allowing the identification of approximately 274 different molecular masses with molecular weights varying from 287 to 43,437 Da. The most abundant peptides were those from 1 K Da and 4–5 K Da representing antimicrobial peptides and putative potassium channel toxins, respectively. Three such peptides were chemically synthesized and tested against Gram-positive and Gram-negative bacteria showing minimum inhibitory concentration in the low micromolar range, but with moderate hemolytic activity. It also reports a transcriptome analysis of the venom glands of the same scorpion species, undertaken by constructing a cDNA library and conducting random sequencing screening of the transcripts. From the resultant cDNA library 172 expressed sequence tags (ESTs) were analyzed. These transcripts were further clustered into 120 unique sequences (23 contigs and 97 singlets). The identified putative proteins can be assorted in several groups, such as those implicated in common cellular processes, putative neurotoxins and antimicrobial peptides. The scorpion U. yaschenkoi is not known to be dangerous to humans and its venom contains peptides similar to those of Opisthacanthus cayaporum (antibacterial), Scorpio maurus palmatus (maurocalcin), Opistophthalmus carinatus (opistoporines) and Hadrurus gerstchi (scorpine-like molecules), amongst others.
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characterization of hadrucalcin a peptide from hadrurus gertschi scorpion venom with pharmacological activity on ryanodine receptors
British Journal of Pharmacology, 2009Co-Authors: Lourival D Possani, Elisabeth F Schwartz, Michelle E Capes, Elia Diegogarcia, Fernando Z Zamudio, Oscar Fuentes, Héctor H. ValdiviaAbstract:Background and purpose: Members of the calcin family, presently including imperatoxin A, maurocalcin, opicalcins and hemicalcin, are basic, 33-mer peptide activators of ryanodine receptors (RyRs), the calcium channels of the sarcoplasmic reticulum (SR) that provide the majority of calcium for muscle contraction. Here we describe hadrucalcin, a novel member of this family. Experimental approach: Hadrucalcin was isolated from the venom of Hadrurus gertschi. Amino acid sequence and mass were determined by Edman degradation and mass spectrometry respectively. A cDNA library was constructed to generate clones for DNA sequence determination. Biological activity of native toxin was confirmed with [3H]ryanodine binding, by using SR vesicles from cardiac and skeletal muscle, and with single skeletal (RyR1) and cardiac (RyR2) channels reconstituted in lipid bilayers. Hadrucalcin was applied to intact ventricular myocytes to investigate effects on calcium transients. The secondary structure of hadrucalcin was computer-modelled by using atomic coordinates from maurocalcin, a structurally similar peptide. Key results: Hadrucalcin is distinguished from previously described congeners by two additional amino acids in its primary sequence and the lack of prominent amphipathicity. Hadrucalcin activated RyRs with high affinity (EC50= 37 nmol·L−1), induced a long-lasting subconductance state on RyR1 and RyR2, and rapidly (lag time ∼2 s) penetrated ventricular cardiomyocytes, eliciting discharge of internal calcium stores and spontaneous contractions. Conclusions and implications: Hadrucalcin is a cell-permeant, powerful activator of RyRs, which has translational potential for targeted delivery of drugs to RyR as novel therapeutic intervention in arrhythmogenic disease.
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transcriptome analysis of the venom gland of the mexican scorpion hadrurus gertschi arachnida scorpiones
BMC Genomics, 2007Co-Authors: Elia Diegogarcia, Elisabeth F Schwartz, Ricardo Rodriguez C De La Vega, Lourival D PossaniAbstract:Scorpions like other venomous animals posses a highly specialized organ that produces, secretes and disposes the venom components. In these animals, the last postabdominal segment, named telson, contains a pair of venomous glands connected to the stinger. The isolation of numerous scorpion toxins, along with cDNA-based gene cloning and, more recently, proteomic analyses have provided us with a large collection of venom components sequences. However, all of them are secreted, or at least are predicted to be secretable gene products. Therefore very little is known about the cellular processes that normally take place inside the glands for production of the venom mixture. To gain insights into the scorpion venom gland biology, we have decided to perform a transcriptomic analysis by constructing a cDNA library and conducting a random sequencing screening of the transcripts.
Simon, Karina Smidt - One of the best experts on this subject based on the ideXlab platform.
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Atividade de peptídeos derivados da peçonha de escorpiões em macrófagos murinos: avaliação da sua influência na resposta à cryptococose.
2014Co-Authors: Simon, Karina SmidtAbstract:Dissertação (mestrado)—Universidade de Brasília, Pós-Graduação em Patologia Molecular, 2014.A ocorrência de infecções causadas por patógenos oportunistas, dentro das UTIs são responsáveis por altos índices de morbidade e mortalidade, caracterizando um grave problema de saúde pública. Um desses patógenos é o Cryptococcus neoformans, um fungo basidiomiceto, causador da criptococose. Essa é uma doença manifestada principalmente por indivíduos imunocomprometidos, onde a incapacidade do organismo desses pacientes de eliminar o fungo acaba por permitir a migração do mesmo para diversos tecidos, incluindo o sistema nervoso. Lá ele se estabelece, causando a meningoencefalite, que é a forma mais grave da doença, e eventual morte. O sucesso terapêutico para a criptococcose é bastante baixo, necessitando-se, então, de novas estratégias para o tratamento da doença. AMPs vem sendo investigados como elementos promissores no tratamento de diversas doenças. Estes peptídeos são encontrados em todos os organismos pluricelulares, onde exercem atividades regulatórias e microbicida. Os peptídeos com atividade protetora do organismo, podem, no caso de animais venenosos, ser expressos constitutivamente nas glândulas de veneno. Considerado que esses peptídeos tem o potencial de eliminar patógenos e alterar a atividade de células relacionadas com a defesa dos organismo, foram testados seis peptídeos para ação fungicida contra o C. neoformans e atividade imunomodulatória com macrófagos murinos. Esses peptídeos foram sintetizados a partir da biblioteca de cDNA das glândulas de veneno de escorpiões das espécies Tityus obscurus, Tityus serrulatus e Hadrurus gerstchi. Testes de atividade hemolítica, atividade citotóxica para células de mamíferos, e capacidade microbicida direta e indireta foram executados para todos os peptídeos. Foi verificada a atividade antinflamatória de dois dos peptídeos, além a da alta tóxicidade para o fungo de um terceiro peptídeo Estes peptídeos apresentaram, na concentração em que foram capazes de exercer suas respectivas atividades, baixa capacidade hemolítica e baixa toxicidade para células de mamíferos. Além disso, foi feito um primeiro esforço para entender a estrutura secundária dos peptídeos com atividades modulatória e microbicida, na tentativa de compreender melhor a ação dessas sequências. A utilização desses peptídeos pode ser considerada promissora para o desenvolvimento de novas terapias para o tratamento da criptococose. __________________________________________________________________________ ABSTRACTThe occurrence of infections caused by opportunistic pathogens within the ICU is responsible for high morbidity and mortality inside the hospitals, featuring a serious public health problem. One of them is the fungus Cryptococcus neoformans, a basidiomycete that is the cause of cryptococcosis. This is a disease manifested mainly in immunocompromised patients, where the body's inability to eliminate the pathogen eventually allow the fungus migration to various tissues, including the nervous system. There it establishes, causing meningoencephalitis, the most severe form of the disease, and eventual death. Successful treatment for cryptococcosis is rather low, so it becomes a necessity to search for new strategies of treatment for this infirmity. Antimicrobial peptides are being investigated as a promising treatment for many illness. These peptides are found in all multicellular organisms, where they exert regulatory and microbicidal activities. The peptides with protective activity of the organism may be expressed constitutively in venom glands, in the case of poisonous animals. Considering that these peptides has the potential to eliminate pathogens and alter the activity of cells related to the defense of the organisms, here we tested six peptides for a fungicide activity against C. neoformans and immunomodulatory capacity in murine macrophages. These peptides were synthesized from the cDNA library of the venom gland of Tityus obscurus, Tityus serrulatus and Hadrurus gerstchi scorpion species. Tests of hemolytic activity, cytotoxic activities to mammalian cells, and direct and indirect microbicidal capacity were performed for all peptides. There was verified the anti-inflammatory activity of two of the peptides, in addition to the high toxicity to the fungus of a third peptide. At the concentration in which they were able to pursue their activities, these peptides presented low hemolytic capacity and low toxicity to mammalian cells. Furthermore, a first effort has been made to understand the secondary structure of peptides with microbicidal and modulatory activities, in an attempt to better understand the action of these sequences. The use of these peptides may be considered promising for the development of new therapies for the treatment of cryptococcosis
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Atividade de peptídeos derivados da peçonha de escorpiões em macrófagos murinos: avaliação da sua influência na resposta à cryptococose.
2014Co-Authors: Simon, Karina SmidtAbstract:A ocorrência de infecções causadas por patógenos oportunistas, dentro das UTIs são responsáveis por altos índices de morbidade e mortalidade, caracterizando um grave problema de saúde pública. Um desses patógenos é o Cryptococcus neoformans, um fungo basidiomiceto, causador da criptococose. Essa é uma doença manifestada principalmente por indivíduos imunocomprometidos, onde a incapacidade do organismo desses pacientes de eliminar o fungo acaba por permitir a migração do mesmo para diversos tecidos, incluindo o sistema nervoso. Lá ele se estabelece, causando a meningoencefalite, que é a forma mais grave da doença, e eventual morte. O sucesso terapêutico para a criptococcose é bastante baixo, necessitando-se, então, de novas estratégias para o tratamento da doença. AMPs vem sendo investigados como elementos promissores no tratamento de diversas doenças. Estes peptídeos são encontrados em todos os organismos pluricelulares, onde exercem atividades regulatórias e microbicida. Os peptídeos com atividade protetora do organismo, podem, no caso de animais venenosos, ser expressos constitutivamente nas glândulas de veneno. Considerado que esses peptídeos tem o potencial de eliminar patógenos e alterar a atividade de células relacionadas com a defesa dos organismo, foram testados seis peptídeos para ação fungicida contra o C. neoformans e atividade imunomodulatória com macrófagos murinos. Esses peptídeos foram sintetizados a partir da biblioteca de cDNA das glândulas de veneno de escorpiões das espécies Tityus obscurus, Tityus serrulatus e Hadrurus gerstchi. Testes de atividade hemolítica, atividade citotóxica para células de mamíferos, e capacidade microbicida direta e indireta foram executados para todos os peptídeos. Foi verificada a atividade antinflamatória de dois dos peptídeos, além a da alta tóxicidade para o fungo de um terceiro peptídeo Estes peptídeos apresentaram, na concentração em que foram capazes de exercer suas respectivas atividades, baixa capacidade hemolítica e baixa toxicidade para células de mamíferos. Além disso, foi feito um primeiro esforço para entender a estrutura secundária dos peptídeos com atividades modulatória e microbicida, na tentativa de compreender melhor a ação dessas sequências. A utilização desses peptídeos pode ser considerada promissora para o desenvolvimento de novas terapias para o tratamento da criptococose. __________________________________________________________________________ ABSTRACTThe occurrence of infections caused by opportunistic pathogens within the ICU is responsible for high morbidity and mortality inside the hospitals, featuring a serious public health problem. One of them is the fungus Cryptococcus neoformans, a basidiomycete that is the cause of cryptococcosis. This is a disease manifested mainly in immunocompromised patients, where the body's inability to eliminate the pathogen eventually allow the fungus migration to various tissues, including the nervous system. There it establishes, causing meningoencephalitis, the most severe form of the disease, and eventual death. Successful treatment for cryptococcosis is rather low, so it becomes a necessity to search for new strategies of treatment for this infirmity. Antimicrobial peptides are being investigated as a promising treatment for many illness. These peptides are found in all multicellular organisms, where they exert regulatory and microbicidal activities. The peptides with protective activity of the organism may be expressed constitutively in venom glands, in the case of poisonous animals. Considering that these peptides has the potential to eliminate pathogens and alter the activity of cells related to the defense of the organisms, here we tested six peptides for a fungicide activity against C. neoformans and immunomodulatory capacity in murine macrophages. These peptides were synthesized from the cDNA library of the venom gland of Tityus obscurus, Tityus serrulatus and Hadrurus gerstchi scorpion species. Tests of hemolytic activity, cytotoxic activities to mammalian cells, and direct and indirect microbicidal capacity were performed for all peptides. There was verified the anti-inflammatory activity of two of the peptides, in addition to the high toxicity to the fungus of a third peptide. At the concentration in which they were able to pursue their activities, these peptides presented low hemolytic capacity and low toxicity to mammalian cells. Furthermore, a first effort has been made to understand the secondary structure of peptides with microbicidal and modulatory activities, in an attempt to better understand the action of these sequences. The use of these peptides may be considered promising for the development of new therapies for the treatment of cryptococcosis
Johansen S. - One of the best experts on this subject based on the ideXlab platform.
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Begroing av vannkvalitet i Surnavassdraget i 1998. Grunnlagsmateriale for konsekvensvurderinger
Norsk institutt for vannforskning, 1999Co-Authors: Johansen S., Lindstrøm E.-a.Abstract:Årsliste 1999Det er foretatt en undersøkelse av vannkvalitet og begroingsforhold i Surnavassdraget i perioden juni - september 1998. I hele hovedvassdraget er næringssalter redusert siden midt på 1980-tallet. Reduserte konsentrasjoner av næringssalter har bl.a. medført endret artsammensetning av begroingsorganismer. Oppstrøms Trollheim kraftverk er fortsatt innholdet av næringssalter og organisk materiale så høyt at det gir grunnalg for begroingsorganismer som trives i næringsrikt svakt forurensningsbelastet vann. Nedstrøms Trollheim kraftstasjon er begroingssamfunnet nå preget av organismer som trives i relativt næringsfattig vann. Det ble registrert større forkomster av kaldtvannsalgene Hydrurus FOETIDUS og ULOTHRIX ZONATA. MICROSPORA AMOENA ble ikke registrert i større forekomst denne sesongen. Dette kan ha flere årsaker hvorav generell reduksjon i næringstilførsler og endret substrat i form av økt forekomst av vannmosen FONTINALIS er de viktigste. Det ble registrert til dels store forkomster av FONTINALIS DALECARLICA nedstrøms Trollheim kraftstasjon, som med stor sannsynlighet har økt gradvis i omfang etter reguleringen. Det er gjort en oppdatering av konsekvensvurderinger for begroing i forbindelse med ENEF tiltak og nye utbyggingsplaner i Surnavassdraget.Statkraft Engineering A/
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Begroing av vannkvalitet i Surnavassdraget i 1998. Grunnlagsmateriale for konsekvensvurderinger
Norsk institutt for vannforskning, 1999Co-Authors: Johansen S., Lindstrøm E.-a.Abstract:Det er foretatt en undersøkelse av vannkvalitet og begroingsforhold i Surnavassdraget i perioden juni - september 1998. I hele hovedvassdraget er næringssalter redusert siden midt på 1980-tallet. Reduserte konsentrasjoner av næringssalter har bl.a. medført endret artsammensetning av begroingsorganismer. Oppstrøms Trollheim kraftverk er fortsatt innholdet av næringssalter og organisk materiale så høyt at det gir grunnalg for begroingsorganismer som trives i næringsrikt svakt forurensningsbelastet vann. Nedstrøms Trollheim kraftstasjon er begroingssamfunnet nå preget av organismer som trives i relativt næringsfattig vann. Det ble registrert større forkomster av kaldtvannsalgene Hydrurus FOETIDUS og ULOTHRIX ZONATA. MICROSPORA AMOENA ble ikke registrert i større forekomst denne sesongen. Dette kan ha flere årsaker hvorav generell reduksjon i næringstilførsler og endret substrat i form av økt forekomst av vannmosen FONTINALIS er de viktigste. Det ble registrert til dels store forkomster av FONTINALIS DALECARLICA nedstrøms Trollheim kraftstasjon, som med stor sannsynlighet har økt gradvis i omfang etter reguleringen. Det er gjort en oppdatering av konsekvensvurderinger for begroing i forbindelse med ENEF tiltak og nye utbyggingsplaner i Surnavassdraget
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Algeproblematikken i Surna ved installasjon av aggregat 2 i Trollheim kraftverk
Norsk institutt for vannforskning, 1998Co-Authors: Johansen S.Abstract:Det er foretatt en gjennomgang av litteratur som omhandler undersøkelser av algebegroing i Surnavassdraget fra perioden 1975 til 1993. Det foreliggende materiale om algebegroing i Surna er ikke tilstrekkelig til å kunne gi en fullverdig konsekvensvurdering av mulige effekter av et aggregat 2 i Trollheim kraftverk. Det er 13 år siden siste befaring i forbindelse med algeproblematikken og reguleringseffekter. Utsagn indikerer at problemer med masseforekomst av grønnalgen Microspora amoena er blitt mindre etter dette. Som et utgangspunkt for en konsekvensvurdering bør det minimum foreligge en kartlegging av dagens situasjon spesielt mhp. forholdet mosebegroing/algebegroing og substratforhold på strekningen nedstrøms Trollheim kraftverk. Med utgangspunkt i det hydrologiske grunnlaget (simulerte vannføringer basert på ukes-produksjon før og etter installasjon av aggregat 2) og simulerte temperaturforhold, kan en trekke følgende konklusjoner: 1. Oppstrøms Trollheim kraftverk vil den nye situasjonen kunne gi bedre forhold for flerårig vegetasjon (moser). Algebegroingen vil bli lite endret i forhold til dagens situasjon. 2. Nedstrøms Trollheim kraftverk vil de hydrologiske og temperaturmessige forhold fortsatt ligge til rette for masseutvikling av kaldtvannsalgene Hydrurus foetidus, Microspora amoena og Ulothrix zonata i tørre og middels nedbørrike år. Høyere vintervannføring kombinert med høyere vanntemperatur i den samme perioden vil kunne gi grunnlag for økt vekst av vannmoser
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Algeproblematikken i Surna ved installasjon av aggregat 2 i Trollheim kraftverk
Norsk institutt for vannforskning, 1998Co-Authors: Johansen S.Abstract:Det er foretatt en gjennomgang av litteratur som omhandler undersøkelser av algebegroing i Surnavassdraget fra perioden 1975 til 1993. Det foreliggende materiale om algebegroing i Surna er ikke tilstrekkelig til å kunne gi en fullverdig konsekvensvurdering av mulige effekter av et aggregat 2 i Trollheim kraftverk. Det er 13 år siden siste befaring i forbindelse med algeproblematikken og reguleringseffekter. Utsagn indikerer at problemer med masseforekomst av grønnalgen Microspora amoena er blitt mindre etter dette. Som et utgangspunkt for en konsekvensvurdering bør det minimum foreligge en kartlegging av dagens situasjon spesielt mhp. forholdet mosebegroing/algebegroing og substratforhold på strekningen nedstrøms Trollheim kraftverk. Med utgangspunkt i det hydrologiske grunnlaget (simulerte vannføringer basert på ukes-produksjon før og etter installasjon av aggregat 2) og simulerte temperaturforhold, kan en trekke følgende konklusjoner: 1. Oppstrøms Trollheim kraftverk vil den nye situasjonen kunne gi bedre forhold for flerårig vegetasjon (moser). Algebegroingen vil bli lite endret i forhold til dagens situasjon. 2. Nedstrøms Trollheim kraftverk vil de hydrologiske og temperaturmessige forhold fortsatt ligge til rette for masseutvikling av kaldtvannsalgene Hydrurus foetidus, Microspora amoena og Ulothrix zonata i tørre og middels nedbørrike år. Høyere vintervannføring kombinert med høyere vanntemperatur i den samme perioden vil kunne gi grunnlag for økt vekst av vannmoser.Statkraft Engineering A/
Elisabeth F Schwartz - One of the best experts on this subject based on the ideXlab platform.
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characterization of hadrucalcin a peptide from hadrurus gertschi scorpion venom with pharmacological activity on ryanodine receptors
British Journal of Pharmacology, 2009Co-Authors: Lourival D Possani, Elisabeth F Schwartz, Michelle E Capes, Elia Diegogarcia, Fernando Z Zamudio, Oscar Fuentes, Héctor H. ValdiviaAbstract:Background and purpose: Members of the calcin family, presently including imperatoxin A, maurocalcin, opicalcins and hemicalcin, are basic, 33-mer peptide activators of ryanodine receptors (RyRs), the calcium channels of the sarcoplasmic reticulum (SR) that provide the majority of calcium for muscle contraction. Here we describe hadrucalcin, a novel member of this family. Experimental approach: Hadrucalcin was isolated from the venom of Hadrurus gertschi. Amino acid sequence and mass were determined by Edman degradation and mass spectrometry respectively. A cDNA library was constructed to generate clones for DNA sequence determination. Biological activity of native toxin was confirmed with [3H]ryanodine binding, by using SR vesicles from cardiac and skeletal muscle, and with single skeletal (RyR1) and cardiac (RyR2) channels reconstituted in lipid bilayers. Hadrucalcin was applied to intact ventricular myocytes to investigate effects on calcium transients. The secondary structure of hadrucalcin was computer-modelled by using atomic coordinates from maurocalcin, a structurally similar peptide. Key results: Hadrucalcin is distinguished from previously described congeners by two additional amino acids in its primary sequence and the lack of prominent amphipathicity. Hadrucalcin activated RyRs with high affinity (EC50= 37 nmol·L−1), induced a long-lasting subconductance state on RyR1 and RyR2, and rapidly (lag time ∼2 s) penetrated ventricular cardiomyocytes, eliciting discharge of internal calcium stores and spontaneous contractions. Conclusions and implications: Hadrucalcin is a cell-permeant, powerful activator of RyRs, which has translational potential for targeted delivery of drugs to RyR as novel therapeutic intervention in arrhythmogenic disease.
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transcriptome analysis of the venom gland of the mexican scorpion hadrurus gertschi arachnida scorpiones
BMC Genomics, 2007Co-Authors: Elia Diegogarcia, Elisabeth F Schwartz, Ricardo Rodriguez C De La Vega, Lourival D PossaniAbstract:Scorpions like other venomous animals posses a highly specialized organ that produces, secretes and disposes the venom components. In these animals, the last postabdominal segment, named telson, contains a pair of venomous glands connected to the stinger. The isolation of numerous scorpion toxins, along with cDNA-based gene cloning and, more recently, proteomic analyses have provided us with a large collection of venom components sequences. However, all of them are secreted, or at least are predicted to be secretable gene products. Therefore very little is known about the cellular processes that normally take place inside the glands for production of the venom mixture. To gain insights into the scorpion venom gland biology, we have decided to perform a transcriptomic analysis by constructing a cDNA library and conducting a random sequencing screening of the transcripts.
Bruno Rossaro - One of the best experts on this subject based on the ideXlab platform.
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microdistribution of chironomids diptera chironomidae in alpine streams an autoecological perspective
Hydrobiologia, 2005Co-Authors: Valeria Lencioni, Bruno RossaroAbstract:Chironomid communities from three glacial and three non-glacial high mountain streams in three Alpine river basins were analyzed (Conca, Niscli, Cornisello, NE Italy, 46° N, 10° E). Eighteen sampling reaches belonging to five stream types (kryal, subkryal, glacio-rhithral, kreno-rhithral, outlet) were investigated. At each reach, geomorphological, physical, chemical and biological data were collected. Field surveys were carried out during three periods per year from 1996 to 1998: immediately after spring snowmelt, in mid-summer and in early autumn. In all, 439 zoobenthos samples were collected from 5 to 10 microhabitats of 0.1 m2 in each reach and date using a standard pond net (mesh size of 250 μm). About 50% of individuals collected were chironomids (26 673 specimens, 53 taxa), with densities ranging from 4 to 2652 ind m−2. With few exceptions, they dominated as number of taxa and individuals in all reaches. Chironomid subfamilies Diamesinae and Orthocladiinae were most abundant, especially in glacial reaches, where Diamesa spp. constituted up to 100% of the total fauna. Chironomid distribution was analyzed in relation to 37 abiotic variables, referring to stream origin, hydrology, geomorphology, physics and chemistry. Diamesa steinboecki, D. latitarsis gr. A and Pseudokiefferiella parva were the taxa best associated with ‘glacial’ conditions (i.e. high channel instability or presence of bedrock, high suspended solids and total phosphorous content, low conductivity and silica content, highly variable diel discharge and low mean temperature), while Pseudodiamesa branickii, Corynoneura spp., Eukiefferiella spp., Parorthocladius nudipennis, Tvetenia calvescens/bavarica, Thienemaniella spp. and Micropsectra atrofasciata were mostly associated with ‘non-glacial’ conditions. Substratum particle size, water depth, current velocity, the presence of riffles/pools and of mosses/algae (Hydrurus foetidus) were the major factors affecting microdistribution of chironomids in the investigated streams.
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Microdistribution of chironomids (Diptera : Chironomidae) in Alpine streams: an autoecological perspective
'Springer Science and Business Media LLC', 2005Co-Authors: Valeria Lencioni, Bruno RossaroAbstract:Chironomid communities from three glacial and three non-glacial high mountain streams in three Alpine river basins were analyzed (Conca, Niscli, Cornisello, NE Italy, 46degrees N, 10degrees E). Eighteen sampling reaches belonging to five stream types (kryal, subkryal, glacio-rhithral, kreno-rhithral, outlet) were investigated. At each reach, geomorphological, physical, chemical and biological data were collected. Field surveys were carried out during three periods per year from 1996 to 1998: immediately after spring snowmelt, in midsummer and in early autumn. In all, 439 zoobenthos samples were collected from 5 to 10 microhabitats of 0.1 m(2) in each reach and date using a standard pond net (mesh size of 250 mum). About 50% of individuals 2 collected were chironomids (26 673 specimens, 53 taxa), with densities ranging from 4 to 2652 ind m(-2). With few exceptions, they dominated as number of taxa and individuals in all reaches. Chironomid subfamilies Diamesinae and Orthocladiinae were most abundant, especially in glacial reaches, where Diamesa spp. constituted up to 100% of the total fauna. Chironomid distribution was analyzed in relation to 37 abiotic variables, referring to stream origin, hydrology, geomorphology, physics and chemistry. Diamesa steinboecki, D. latitarsis gr. A and Pseudokiefferiella parva were the taxa best associated with 'glacial' conditions (i.e. high channel instability or presence of bedrock, high suspended solids and total phosphorous content, low conductivity and silica content, highly variable diel discharge and low mean temperature), while Pseudodiamesa branickii, Corynoneura spp., Eukiefferiella spp., Parorthocladius nudipennis, Tvetenia calveseens/bavarica, Thienemaniella spp. and Micropsectra atrofasciata were mostly associated with 'non-glacial' conditions. Substratum particle size, water depth, current velocity, the presence of riffles/pools and of mosses/algae (Hydrurus foetidus) were the major factors affecting microdistribution of chironomids in the investigated streams