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  • Resumo IPEN-doc 13668
    Immunological properties of sup(60)Co gamma rays irradiated bothropstoxin-I
    2008 - BAPTISTA, J.A.; VIEIRA, D.P.; GALISTEO JUNIOR, A.J.; CAPRONI, P.; CASARE, M.; ANDRADE JUNIOR, H.F.; SPENCER, P.J.; NASCIMENTO, N.
  • Artigo IPEN-doc 10724
    Influence of reactive radicals OH and Esup(-)sub(AQ) in irradiation of protein in aqueous solutions
    2005 - BACETI, A.A.; CESARE, M.; SPENCER, P.J.; NASCIMENTO, N.
    Gamma irradiation of aqueous proteins solutions promotes structural modifications. This is mainly caused by OH • and eaq activity, reactive species produced by water radiolys. The objective of this study was to investigate the role of OH • and eaq in conformation changes observed in proteins irradiated in aqueous solutions. Substances that react specifically with OH • or eaq producing stable products were used in order to study each reactive species’ function: nitrate for eaq and t-butilic alcohol for OH • . Crotamine was used as test peptide. It is composed of 42 aminoacids, which are strongly reticulated by three disulfide bonds. This confers it a very compact conformation leading to high temperatures resistance. Crotamine also has a biological effect: mice hind limb distention. Samples of crotamine in aqueous solution were irradiated in order to analyze the activity of OH • and eaq. Some contemned t-butilic alcohol and others, sodium nitrate; the results were compared to control samples with no neutralizing substances. To verify possible protein conformation change due to sodium nitrate or t-butilic alcohol addition, samples with different concentrations of these substances were prepared, kept without irradiation and their results were compared to only protein solution. Samples were also submitted to a biological test Samples were submitted to SDS-PAGE, which did not show any alteration in those samples with t-butilic alcohol or sodium nitrate. In addition, the samples had their absorbance spectrum of 200 nm to 360 nm scanned which showed less conformation change in irradiated with t-butilic then only protein one. Irradiated samples had less biological effect than non-irradiated ones.
  • Artigo IPEN-doc 11952
    Structure alteration and immunological properties of sup(60)Co gamma rays irradiated bothropstoxin-I
    2007 - BAPTISTA, JANAINA A.; VIEIRA, DANIEL P.; GALISTEO JUNIOR, ANDRES J.; YONAMINE, CAMILA M.; CAPRONI, PRISCILA; CASARE, MURILO; ANDRADE JUNIOR, HEITOR F. de; SPENCER, PATRICK J.; NASCIMENTO, NANCI do
  • Artigo IPEN-doc 09897
    Effects of gamma rays on the immunogenicity (IgG types) of ovalbumin
    2004 - BAPTISTA, J.A.; SPENCER, P.J.; AROEIRA, L.G.S.; CASARE, M.S.; NASCIMENTO, N.
  • Artigo IPEN-doc 09896
    Effects of sup(60)Co radiation on the molecular structure of crotamine
    2004 - CASARE, M.S.; BAPTISTA, J.A.; SPENCER, P.J.; NASCIMENTO, N.
  • Artigo IPEN-doc 11621
    Study of gamma-radiation effects on crotamine and crotoxin
    2006 - CASARE, M.S.; SPENCER, P.; CAMPOS, L.A.; NASCIMENTO, N.
    Crotoxin is a 23 kDa neurotoxin from Crotalus durissus terrificus and is composed of a 9 kDa acidic subunit (crotapotin) and a 14 kDa basic subunit (phospholipase A2). Crotamine is 4882 Da, basic polypeptide with myotoxic activity. These toxins, when submitted to gamma-rays, in aqueous solution, present structural modifications, preserving their immunogenic properties. In the present work, we investigated some structural modifications on both crotoxin and crotamine after gamma-radiation using various doses, in the presence or not of "scavenger" substances. Our results indicate that irradiation leads to progressive changes in the structure of the toxin, which could explain the lower toxicity observed.
  • Artigo IPEN-doc 14173
    Immunological properties of sup(60)Co gamma-rays irradiated bothropstoxin-I
    2009 - BAPTISTA, J.A.; VIEIRA, D.P.; GALISTEO JUNIOR, A.J.; CAPRONI, P.; CASARE, M.; ANDRADE JUNIOR, H.F. de; SPENCER, P.J.; NASCIMENTO, N.