title: Enzymatic activity of toxic and non-toxic type 2 ribosome-inactivating proteins.
abstract: Ribosome-inactivating proteins (RIPs) display adenine polynucleotide glycosylase activity on different nucleic acid substrates, which at the ribosomal level is responsible for the arrest of protein synthesis. Some type 2 RIPs, namely ricin and related proteins, are extremely toxic to mammalian cells and animals whilst other type 2 RIPs (non-toxic type 2 RIPs) display three to four logs less toxicity. We studied whether a correlation exists between toxicity on cells and enzymatic activity on nucleic acids. All type 2 RIPs differ in their depurinating activity on the different substrates with differences of up to one to two logs. The toxicity of type 2 RIPs is independent of their enzymatic activity on nucleic acids or on ribosomes.
authors.affiliation: Dipartimento di Patologia Sperimentale, Università di Bologna, I-40126 Bologna, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Barbieri
authors.forename: Marialibera
authors.initials: M
authors.lastname: Ciani
authors.forename: Tomás
authors.initials: T
authors.lastname: Girbés
authors.forename: Wang-Yi
authors.initials: WY
authors.lastname: Liu
authors.forename: Els J M
authors.initials: EJ
authors.lastname: Van Damme
authors.forename: Willy J
authors.initials: WJ
authors.lastname: Peumans
authors.forename: Fiorenzo
authors.initials: F
authors.lastname: Stirpe
mesh_terms: D000036:Abrin / Q000633:toxicity; D020418:Algal Proteins; D000818:Animals; D004798:Enzymes / Q000378:metabolism*; D006023:Glycoproteins / Q000633:toxicity; D008862:Microsomes, Liver / Q000737:chemistry; D009699:N-Glycosyl Hydrolases / Q000378:metabolism; D037121:Plant Lectins / Q000378:metabolism / Q000633:toxicity; D028321:Plant Preparations / Q000633:toxicity; D010940:Plant Proteins / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D012269:Ribosomal Proteins / Q000378:metabolism*; D054788:Ribosome Inactivating Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D012270:Ribosomes / Q000378:metabolism; D012276:Ricin / Q000633:toxicity; D013379:Substrate Specificity; D014118:Toxins, Biological / Q000633:toxicity
chemical_list: D020418:Algal Proteins; D004798:Enzymes; D006023:Glycoproteins; D037121:Plant Lectins; D028321:Plant Preparations; D010940:Plant Proteins; D011506:Proteins; D012269:Ribosomal Proteins; D054790:Ribosome Inactivating Proteins, Type 2; C017707:Ricinus communis agglutinin-1; C050600:Sambucus nigra lectins; D014118:Toxins, Biological; C107391:ebulin r protein, Sambucus ebulus; C009674:ribosome inactivating protein, Viscum; C061930:cinnamomin, Phytophthora cinnamomi; D000036:Abrin; C016004:modeccin; D012276:Ricin; C049134:volkensin; D009699:N-Glycosyl Hydrolases; D054788:Ribosome Inactivating Proteins