Physico-chemical characterization of gamma rays irradiated crotamine
Carregando...
Data
Data de publicação
2009
Orientador
Título da Revista
ISSN da Revista
Título do Volume
É parte de
É parte de
É parte de
É parte de
INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE; MEETING ON NUCLEAR APPLICATIONS, 9th; MEETING ON REACTOR PHYSICS AND THERMAL HYDRAULICS, 16th; MEETING ON NUCLEAR INDUSTRY, 1st
Exportar
Resumo
Ionizing radiation can change the molecular structure and affect the biological properties of
biomolecules. It has been employed to attenuate animal toxins. Crotamine, a toxin from Crotalus durissus
terrificus (Cdt), is a highly basic polypeptide (pI - 10.3), with myotoxic activity and molecular weight of 4882
Da. It is composed of 42 amino acids residues and reticulated by three disulfide bonds. This study aimed the
characterization of irradiated crotamine using Circular Dichroism (CD), Fluorescence Spectroscopy and
Differential Scanning Calorimetry (DSC) techniques. We used size exclusion and ion-exchange chromatography
to purify it from Cdt crude venom. The pure crotamine was irradiated with 2.0 kGy from a 60Co source. Native
and irradiated crotamine were analyzed in a fluorescence spectrophotometer (Hitachi F-4500), under excitation
wavelength at 275 nm and the emission was scanned from 300 to 500 nm. The analysis of fluorescence
quenching showed that the irradiated form displayed a lower quantum yield when compared to the native form.
CD spectra, obtained from a Jasco, J-180 spectropolarimeter, of native and irradiated crotamine solutions,
showed a discrete change between the samples, from apparently ordered conformation to a random coil. Finally,
the thermodynamics analysis, realized in a calorimeter METTLER TOLEDO, DSC 822e, showed that
irradiation promoted changes in the calorimetric profile. Our results indicate that irradiation leads to progressive
changes in the structure of the toxin, which could explain the decrease in myotoxic activity.
Como referenciar
OLIVEIRA, KARINA C. de; SPENCER, PATRICK J.; NASCIMENTO, NANCI. Physico-chemical characterization of gamma rays irradiated crotamine. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE; MEETING ON NUCLEAR APPLICATIONS, 9th; MEETING ON REACTOR PHYSICS AND THERMAL HYDRAULICS, 16th; MEETING ON NUCLEAR INDUSTRY, 1st, September 27 - October 2, 2009, Rio de Janeiro, RJ. Proceedings... Disponível em: http://repositorio.ipen.br/handle/123456789/16571. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.