Ionizing radiation effect on crotamine

Ionizing radiation can change the molecular structure and it affects the biological properties of the biomolecules and this has been employed to attenuate toxins. Crotamine is a strongly basic polypeptide (pI 10.3) from the venom crotallus durissus terrificus, composed of 42 aminoacid residues (Laure, 1075). It produces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. Thus, the objective of this paper was to carry out a biochemical study and a toxic activity assay of the native and irradiated crotamine. crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography. It was irradiated at 2 mg/ml in 0.15 M NaCl solution with 2.0 kGy gamma radiation produced by a 60 Co source. the native and irradiated crotamine were evaluated by biochemical studies and toxic activity (LD50). Preliminary results showed that irradiation has not changed the protein the concentration neither the electroforetic profile although it has caused alteration in ultraviolet absorption spectrum. Irradiated crotamine appeared to be less toxic than native one. (author)