The deoxyribonuclease activity attributed to ribosome-inactivating proteins is due to contamination.
Eur J Biochem
; 258(2): 540-5, 1998 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-9874221
ABSTRACT
The mode of action of ribosome-inactivating proteins (RIPs) has, for many years, been considered to be depurination of a specific adenyl residue of ribosomal RNA, resulting in inhibition of protein synthesis. Recently, this view has been challenged by the observation that many RIP preparations have significant DNase activity in addition to their N-glycosidase activity. In this study, we have investigated the putative DNase activity of two RIPs, ricin and pokeweed antiviral protein (PAP), and show that, in both cases, the DNase activity is due to the presence of contaminating nucleases. The N-glycosidase and DNase activities of PAP were separately and specifically inactivated by chemical modification and heat. Gel filtration of ricin allowed physical separation of the two activities. Furthermore, neither recombinant PAP nor recombinant ricin A-chain purified from Escherichia coli displayed DNase activity.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Ribosomas
/
Desoxirribonucleasas
Idioma:
En
Revista:
Eur J Biochem
Año:
1998
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM