Contrasting Effects of Guanidinium Chloride and Urea on the Activity and Unfolding of Lysozyme.

ABSTRACT: Cosolvents play an important role in regulating the stability and function of proteins present in the cell. We studied the role of cosolvents, urea and guanidinium chloride (GdmCl), which act as protein denaturants, in the catalytic activity and structural stability of the protein lysozyme using activity measurements, spectroscopy, and molecular dynamics simulations. We find that the activity of lysozyme increases on the addition of urea, whereas it decreases sharply on the addition of GdmCl. At low GdmCl concentrations ([GdmCl] < 4 M), the activity of lysozyme decreases, even though there is no significant perturbation in the structure of the lysozyme folded state. We find that this is due to the strong interaction of the Gdm⁺ ion with the residues Asp52 and Glu35, which are pr

SUBMITTER: Biswas B 

PROVIDER: S-EPMC6644995 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature