Partitioning of whey proteins, bovine serum albumin and porcine insulin in aqueous two-phase systems

摘要

Partitioning of the proteins from cheese whey, bovine serum albumin and porcine insulin were analysed using aqueous two-phase systems (ATPS) prepared with PEG-phosphate. PEG-citrate and PEG-maltodextrin (MD). Proteins were quantified through one of the following methods: FPLC, Bradford and spectrophotometry at 280 nm. Results showed that whey proteins partitioned unevenly on the phases of the systems used, with a-lactoaIbumin (a-La) concentrated in the upper phase and ~-lactoglobulin (~-Lg) in the lower. Albumin in PEG-MD systems concentrated in the MD-rich lower phase. Porcine insulin showed great affinity with the PEG-rich phase, its partition coefficient was always over 10 and increases with PEG molecular mass.