IFISE   05411
INSTITUTO DE FISIOLOGIA EXPERIMENTAL
Unidad Ejecutora - UE
artículos
Título:
Molecular mechanism and influence of homogenate mass and phase volume ratio
Autor/es:
IMELIO, N.; MARINI, A.; SPELZINI, D.; PICO GUILLERMO; FARRUGGIA, B
Revista:
J. Chromatography B
Editorial:
Elsevier
Referencias:
Lugar: Dublin; Año: 2008 vol. 873 p. 133 - 138
Resumen:
Pepsin partitioning, a gastric acid protease, in aqueous two-phase systems of polyethyleneglycol/
potassium phosphate, sodium citrate and ammonium sulphate was assayed using polyethylenglycol
of different molecular mass. Pepsin was found to be partitioned towards the polymer-rich phase in all
the systems, which suggests an important proteinpolymer interaction due to the highly hydrophobic
character of the protein surface exposed to the solvent. The pepsin partitioning behavior was explained
according to Timasheffs preferential interaction theory. The process was driven entropically with participation
of structured water around the polyethyleneglycol ethylenic chains. The best pepsin recovery was
observed in the systems polyethyleneglycol molecular mass 600. These systems were chosen in order to
assay the bovine stomach homogenate partition and to compare different working conditions such as the
top-bottom phase volume ratio and homogenate proportions in the total system. The best purification
factors were obtained with PEG600/potassium phosphate with low top-bottom volume ratio using 15%
of bovine stomach homogenate in the system total mass.