Comparison of NMR structural and dynamics features of the urea and guanidine-denatured states of GED.
Denatured states of proteins, the starting points as well as the intermediates of folding in vivo, play important roles in biological function. In this context, we describe here urea unfolding and characterization of the denatured state of GTPase effector domain (GED) of dynamin created by 9.7 M urea. These are compared with similar data for guanidine induced denaturation reported earlier. The unfolding characteristics in the two cases, as measured by the optical probes, are significantly different, urea unfolding proceeding via an intermediate. The structural and motional characteristics, determined by NMR, of the two denatured states are also strikingly different. The urea-denatured state shows a combination of alpha- and beta-preferences in contrast to the entirely beta-preferences in the guanidine-denatured state. Higher (15)N transverse relaxation rates suggest higher folding propensities in the urea-denatured state. The implications of these to GED folding are discussed.
Chugh
Jeetender
J
Department of Chemical Sciences, Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Mumbai-400005, India.
Sharma
Shilpy
S
Hosur
Ramakrishna V
RV
D002942:Circular Dichroism; D020558:GTP Phosphohydrolases / Q000737:chemistry* / Q000187:drug effects*; D019791:Guanidine / Q000494:pharmacology*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D011489:Protein Denaturation; D013050:Spectrometry, Fluorescence; D014466:Ultraviolet Rays; D014508:Urea / Q000494:pharmacology*
D014508:Urea; D020558:GTP Phosphohydrolases; D019791:Guanidine