This report describes an integrated investigation of the refolding and reductive unfolding of insulin-like growth factor (IGF-I) and its variant, long R IGF-I (LRIGF-I), which has a Glu to Arg substitution and a hydrophobic 13-amino acid N-terminal extension. The refolding performed in glutathione redox buffer was quenched at different time points by adjusting the pH to 2.0–3.0 with a 1 N HCl s...

The GroEL/GroES chaperonin system acts as a passive anti-aggregation cage for refolding rubisco and rhodanese, and not as an active unfolding device. Refolding aconitase is too large to enter the cage but reversible binding to GroEL reduces its aggregration. Unexpectedly, confinement in the cage increases the rate of refolding of rubisco, but not rhodanese.

BACKGROUND Escherichia coli has been most widely used for the production of valuable recombinant proteins. However, over-production of heterologous proteins in E. coli frequently leads to their misfolding and aggregation yielding inclusion bodies. Previous attempts to refold the inclusion bodies into bioactive forms usually result in poor recovery and account for the major cost in industrial pr...

The properties of molecular chaperones in protein-assisted refolding were examined in vitro using recom-binant human cytosolic chaperones hsp9O, hsc7O, hsp7O and hdj-1, and unfolded 3-galactosidase as the sub-strate. In the presence of hsp7O (hsc7O), hdj-1 and either ATP or ADP, denatured 3-galactosidase refolds and forms enzymatically active tetramers. Interactions between hsp9O and non-native...

Role of disulfide bridges in phytase's unfolding-refolding was probed using dynamic light scattering. Phytase was unfolded by guanidinium chloride and then refolded by removing the denaturant by dialysis. Thiol reagents prevented refolding; thus, disulfide bridge formation is an integral step in phytase folding. Catalytic demise of phytase after unfolding and refolding in presence of Tris(2-car...

Protein disulphide isomerase (PDI) shows chaperone and anti-chaperone activities in assisting refolding of denatured and reduced lysozyme in redox Hepes buffer, but only chaperone activity in phosphate buffer and redox Hepes buffer containing 0.1 M NaCl. In non-redox Hepes buffer its anti-chaperone activity is very weak. PDI displays its anti-chaperone activity only for those substrates showing...

Background: The refolding of proteins from inclusion bodies is affected by several factors, including solubilization of inclusion bodies by denaturants, removal of the denaturant, and assistance of refolding by small molecule additives. Objectives: The purpose of this study was optimization of recombinant human interferon-b purification in order to achieve higher efficiency, yield, and a produ...