Extração de proteinas em um sistema de duas fases aquosas numa micro-coluna pulsada

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Aqueous two-phase systems have found widespread use in biochemical research for separation and purification of macromolecules, cells and cell partic1es. In recent years the aqueous two-phase systems have also found applications in various areas of biotechnology, specially when utilising low-cost biphasic systems, as the new aqueous two-phase system based on cashew-nut tree gum (POLICAJU) and poly(ethylene glycol) (PEG). The exsudate gum from Anacardium occidentale L. is a branched acidic heteropolysaccharide found in Brazilian north-westem. It s employed locally as a substitute for arabic gum in pharmaceutical uses. Crude gum was collected as natural exsudate from cultivated trees in Pemambuco state. Clear nodules free of bark were selected to be isolated via ethanol precipitation. Phase diagrams were provided for POLICAJU and PEG molecular weight of 1500, 4000 and 8000 at pH 6,0, 7,0 and 8,0, for 25°C. It was observed a displacement of the binodal for higher polymer concentrations when polyethylene glycol molecular weights decreased. The pH range studied, did not promote significant alterations on the binodal. Different tie-lines were analysed for partition coefficient determination of a model protein, trypsin. The protein partitioned almost in the bottom gum-rich phase for the experimental conditions tested. The increase of the tie-line length promoted and PEG molecular weight variation, in general, a decreased of the protein partition coefficient. The partition coefficient did not show a regular tendency with the pH range studied

ASSUNTO(S)

caju extração por solventes biomoleculas separação (tecnologia)

ACESSO AO ARTIGO

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