Characterization and evaluation of the enzymatic activity of tetanus toxin submitted to cobalt-60 gamma radiation

Autor(es)

Sartori, Giselle Pacifico ^[1] ; da Costa, Andrea ^[1] ; dos Santos Macarini, Fernanda Lucio ^[2] ; Ceolin Mariano, Douglas Oscar ^[3] ; Pimenta, Daniel Carvalho ^[3] ; Spencer, Patrick Jack ^[4] ; da Silva Nali, Luiz Henrique ^[5] ; Galisteo Jr, Andres Jimenez

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Trop Med, Lab Protozool, IMT FMUSP, Sao Paulo, SP - Brazil

^[2] Butantan Inst, Anaerob Vaccines Sect, Sao Paulo, SP - Brazil

^[3] Butantan Inst, Lab Biochem & Biophys, Sao Paulo, SP - Brazil

^[4] Nucl & Energy Res Inst, Biotechnol Ctr, IPEN, CNEN SP, Sao Paulo, SP - Brazil

^[5] Univ Santo Amaro, Hlth Sci, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Venomous Animals and Toxins including Tropical Diseases; v. 27, APR 30 2021.
• Citações Web of Science: 0

Resumo

Abstract Background Tetanus toxin blocks the release of the inhibitory neurotransmitters in the central nervous system and causes tetanus and its main form of prevention is through vaccination. The vaccine is produced by inactivation of tetanus toxin with formaldehyde, which may cause side effects. An alternative way is the use of ionizing radiation for inactivation of the toxin and also to improve the potential immunogenic response and to reduce the post-vaccination side effects. Therefore, the aim of this study was to characterize the tetanus toxin structure after different doses of ionizing radiation of 60Co. Methods Irradiated and native tetanus toxin was characterized by SDS PAGE in reducing and non-reducing conditions and MALD-TOF. Enzymatic activity was measured by FRET substrate. Also, antigenic properties were assessed by ELISA and Western Blot data. Results Characterization analysis revealed gradual modification on the tetanus toxin structure according to doses increase. Also, fragmentation and possible aggregations of the protein fragments were observed in higher doses. In the analysis of peptide preservation by enzymatic digestion and mass spectrometry, there was a slight modification in the identification up to the dose of 4 kGy. At subsequent doses, peptide identification was minimal. The analysis of the enzymatic activity by fluorescence showed 35 % attenuation in the activity even at higher doses. In the antigenic evaluation, anti-tetanus toxin antibodies were detected against the irradiated toxins at the different doses, with a gradual decrease as the dose increased, but remaining at satisfactory levels. Conclusion Ionizing radiation promoted structural changes in the tetanus toxin such as fragmentation and/or aggregation and attenuation of enzymatic activity as the dose increased, but antigenic recognition of the toxin remained at good levels indicating its possible use as an immunogen. However, studies of enzymatic activity of tetanus toxin irradiated with doses above 8 kGy should be further analyzed. (AU)

• Processo FAPESP: 14/26782-8 - Avaliação da proteção contra a formação de cistos cerebrais em camundongos imunizados com taquizoítos irradiados de diferentes cepas de Toxoplasma gondii
• Beneficiário: Andrés Jimenez Galisteo Jr
• Modalidade de apoio: Auxílio à Pesquisa - Regular