Takeshi Furuya

Measurement and correlation of liquid-liquid equilibria and partition coefficients of hydrolytic enzymes for DEX T500 + PEG20000 + water aqueous two-phase system at 20 °C

Abstract The liquid-liquid equilibria (LLE) for the dextran T500 (DEX T500) + poly(ethylene glycol) 20000 (PEG20000) + water aqueous two-phase system were measured at 20 °C. Furthermore, the molecular weight distributions of DEX and PEG in the top and bottom phases were measured. The partition coefficients (Kp) of hydrolytic enzymes, α-amylase, β-amylase and glucoamylase were also measured. LLE and Kp were correlated using a modified Flory-Huggins equation developed for aqueous systems. The molecular weight distribution of DEX was expressed by a Γ distribution function. LLE and molecular weight distributions were correlated successfully using a continuous thermodynamic approach. The partition coefficients were also correlated with good agreement.

Measurement and correlation of liquid-liquid equilibria for dextranpoly(ethylene glycol)water aqueous two-phase systems at 20°C

Abstract The liquid-liquid equilibria (LLE) for the dextranpoly(ethylene glycol)water aqueous two-phase systems with various polymer molecular weights were measured at 20°C. The molecular weight distributions of dextran (DEX) and poly(ethylene glycol) (PEG) in the PEG-rich phase (top phase) and DEX-rich phase (bottom phase) were also measured. To take into account deviations from random mixing, the interaction term of the conventional Flory-Huggins equation was empirically modified. The molecular weight distribution of DEX was expressed by a Γ distribution function because the DEX sample used showed a wide molecular weight distribution though the PEG samples were almost monodispersed. LLE and molecular weight distributions were correlatet successfully using a continuous thermodynamic approach.

Measurement and correlation of partition coefficients of hydrolytic enzymes for dextran+poly (ethylene glycol) + water aqueous two-phase systems at 20°C

Abstract The partition coefficients of hydrolytic enzymes, α-amylase, β-amylase and glucoamylase for the dextran (DEX)+poly(ethylene glycol) (PEG)+water aqueous two-phase systems with various polymer molecular weights were measured at 20°C. The partition coefficients obtained were correlated by using a mod fied Flory-Huggins equation which was empirically proposed for aqueous systems. The interaction parameters required were determined by fitting the model to the experimental data. The partition coefficients could be correlated with good agreement.

Measurement and Correlation of Phase Equilibria if Aqueous Two-Phase Systems and Partition Coefficients by Enzymes

ABSTRACT Furuya, T., Nakada, K., Iwai, Y., Arai, Y. and Takeuchi, K., 1990. Measurement and correlation of phase equilibria of aqueous two-phase systems and partition coefficients of enzymes. Aqueous two-phase systems provide a successful method for separating biomolecules by extraction under mild condition. Nevertheless, the phase equilibrium data of aqueous two-phase systems and the partition coefficient data of biomolecules are scarce and it is difficult to correlate them quantitatively. In the present work, the phase equilibria for the dextran-polyethylene glycol-water aqueous two-phase systems are measured. The partition coefficients of enzymes are also measured. Further, the osmotic virial equation is used to correlate the phase equilibria of the aqueous two-phase systems and the partition coefficients of enzymes.