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Updated: Jul 2, 2026
Organic Solvent-Based Protein Precipitation for Robust Proteome Purification Ahead of Mass Spectrometry
Published on: February 7, 2022
Optimization of conditions for acid protease partitioning and purification in aqueous two-phase systems using
Draginja M Pericin1, Senka Z Madarev-Popović, Ljiljana M Radulović-Popović
1Department of Applied and Engineering Chemistry, Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, Novi Sad, Serbia.
Abstract:
Aspergillopepsin I, an acid protease, was purified using an aqueous two-phase system that comprised various combinations of polyethylene glycol (PEG), NaH2PO4 and NaCl. Partition of the enzyme depended upon the molecular mass of the PEG and the presence of NaCl. With PEG 1500, 4000 and 6000, the partition coefficients were increased by 1,500-, 1,800- and 560-fold compared to values without NaCl. The presence of NaCl (8.75%, w/w) increased purification by 3.8, 9.5 and 2.8 times into these respective PEGs. The optimal aqueous two-phase system for acid protease purification was developed using response surface methodology. This system contained 17.3% of PEG 4000 (w/w), 15% NaH2PO4 (w/w) and 8.75% NaCl (w/w) and provided the best partition coefficient (Ke > 1,100) and yield over 99% in the same phase. The optimal ATPS purification factor of acid protease was over 5.
