title: Three phase partitioning leads to subtle structural changes in proteins.
abstract: Three phase partitioning consists of precipitation of proteins due to simultaneous presence of ammonium sulphate and t-butanol. The technique has been successfully used for purification and refolding of proteins. There are however indications that the structures of proteins subjected to three phase partitioning are different from native structure of proteins. Taking several proteins, the present work examines the structural changes in proteins by comparing their thermal stabilities, secondary structure contents, surface hydrophobicities, hydrodynamic radii and solubilities in the presence of ammonium sulphate. The results show that while the nature or extent of structural changes may vary, in all the cases the changes are rather subtle and not drastic in nature. Hence, the technique can be safely used for protein purification and refolding.
authors.affiliation: Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Gulam Mohmad
authors.initials: GM
authors.lastname: Rather
authors.forename: Munishwar Nath
authors.initials: MN
authors.lastname: Gupta
mesh_terms: D004798:Enzymes / Q000737:chemistry / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D004798:Enzymes; D011506:Proteins
keywords: Circular dichroism of proteins; Enzymes in low water media; Protein flexibility; Protein purification; Protein refolding; Three phase partitioning