Denaturation studies of Clarias gariepinus glutathione transferase in dilute and crowded solutions.

Denaturation studies of Clarias gariepinus glutathione transferase in dilute and crowded solutions. Eur Biophys J. 2019 Oct 25;: Authors: Ogunmoyole T, Fodeke AA, Adewale IO Abstract It is important to understand the effect of crowding conditions on the native structure and functional state of enzymes. Equilibrium denaturation studies of Clarius gariepinus GST (CgGST) by guanidine hydrochloride (GdHCl) under dilute conditions and in separate solutions of 0-100 g dm-3 Ficoll 70, polyethylene glycol 6000 (PEG 6000) and equal w/v mixtures of the two polymers at 25 °C and pH 7.4 were studied fluorometrically. The data were analyzed based on a two-state model assuming the native protein dimer separates into two monomers and then unfolds. The standard free energy of unfolding (ΔG°UN) increases with increasing concentration of each crowding agent in a manner suggesting that high concentrations of PEG 6000 and Ficoll 70 favour the native CgGST relative to the unfolded form. Ficoll 70 stabilizes the native CgGST better than PEG 6000 at low w/v concentration. A mixture of equal g/cm3 concentrations of both crowding agents, however, stabilizes the native form more effectively than either Ficoll 70 or PEG 6000 at equivalent w/v total concentration and is less sensitive to GdHCl. This is in strong agreement with the results of refolding studies, and suggests that a mixture of molecular crowders of widely different molecular weights might sh...
Source: European Biophysics Journal : EBJ - Category: Physics Authors: Tags: Eur Biophys J Source Type: research