Novel polyethylene glycol/levan aqueous two-phase system for protein partitioning

Abstract

A novel aqueous two-phase system was made by mixing PEG (polyethylene glycol) and levan. The partitioning experiments were performed with six model proteins: horse heart cytochrome c, horse hemoglobin, horse heart myoglobin, hen egg albumin, bovine serum albumin and hen egg lysozyme. The addition of NaCl increased the partition coefficient of lysozyme but decreased that of albumin. The partition coefficients were sensitive to pH, increasing in the pH range of 6 to 8 for five of the proteins tested and decreasing slightly for lysozyme.