Isolation and characterization of four type 2 ribosome inactivating pulchellin isoforms from Abrus pulchellus seeds
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
20/10/2012
20/10/2012
2008
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Resumo |
Abrus pulchellus seeds contain at least seven closely related and highly toxic type 2 ribosome-inactivating pulchellins, each consisting of a toxic A-chain linked to a sugar binding B-chain. In the present study, four pulchellin isoforms (termed P I, P II, P III and P IV) were isolated by affinity, ion exchange and chromatofocusing chromatographies, and investigated with respect to toxicity and sugar binding specificity. Half maximal inhibitory concentration and median lethal dose values indicate that P I and P II have similar toxicities and that both are more toxic to cultured HeLa cells and mice than P III and P IV. Interestingly, the secondary structural characteristics and sugar binding properties of the respective pairs of isoforms correlate well with the two toxicity levels, in that P I/P II and P III/P IV form two specific subgroups. From the deduced amino acids sequences of the four isoforms, it is clear that the highest similarity within each subgroup is found to occur within domain 2 of the B-chains, suggesting that the disparity in toxicity levels might be attributed to subtle differences in B-chain-mediated cell surface interactions that precede and determine toxin uptake pathways. |
Identificador |
FEBS JOURNAL, v.275, n.5, p.948-959, 2008 1742-464X http://producao.usp.br/handle/BDPI/30049 10.1111/j.1742-4658.2008.06258.x |
Idioma(s) |
eng |
Publicador |
BLACKWELL PUBLISHING |
Relação |
Febs Journal |
Direitos |
restrictedAccess Copyright BLACKWELL PUBLISHING |
Palavras-Chave | #Abrus pulchellus #characterization #cloning #isoforms #ribosome-inactivating protein #INHIBITING PROTEIN-SYNTHESIS #CONSTITUENT-PEPTIDE CHAINS #MISTLETOE LECTIN I #RICIN-B-CHAIN #VISCUM-ALBUM #TOXIC LECTIN #HETEROLOGOUS EXPRESSION #CRYSTAL-STRUCTURE #A-CHAIN #PURIFICATION #Biochemistry & Molecular Biology |
Tipo |
article original article publishedVersion |