Cell toxicity by ricin and elucidation of mechanism of Ricin inactivation.
Int J Biol Macromol
; 113: 821-828, 2018 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-29522821
Castor cake is a by-product of the extraction of oil from from seeds of castor plants (Ricinus communis). This by-product contains high levels of proteins, but a toxic protein, ricin, limits its use as an animal feed. Ricin can be efficiently inactivated by treatment with calcium oxide (CaO), which can be evaluated by a cytotoxicity assay using LLC-MK2 cells. The mechanism by which the CaO treatment inactivates ricin, however, is unclear. We report the structural changes responsible for ricin inactivation. Purified ricin was treated with 0.6% CaO and then analyzed by mass spectrometry. This treatment degraded the ricin at preferential sites. The aqueous CaO solution had a pH >12, which preferentially cleaved asparagine residues, followed by glutamine, serine and glycine residues. The alkaline pH affected the tertiary structure of the ricin, cleaving its polypeptide chains and thereby eliminating its cytotoxic activity.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ricina
/
Citotoxinas
Limite:
Animals
Idioma:
En
Revista:
Int J Biol Macromol
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda