[Investigation of folding/unfolding kinetics of apomyoglobin].
Apomyoglobin kinetic and equilibrium unfolding and folding processes were studied at pH 6.2, 11 degrees C by stopped-flow tryptophan fluorescence. There are two distinct consecutive processes in apomyoglobin folding process, namely, the protein fast transition between the unfolded (U) and an intermediate (I) states (U <----> I) and slow transition between the intermediate and the native (N) states (I <----> N). Accumulation of the intermediate state was observed in the wide range of urea concentrations. The presence of the intermediate state was shown even beyond the middle transition on the unfolding limb. The dependence of observed folding/unfolding rates on urea concentration (chevron plot) was obtained. The shape of this dependence was compared with that of two-state proteins, folding from the U to N state.
Baryshnikova
E N
EN
Mel'nik
B S
BS
Semisotnov
G V
GV
Bychkova
V E
VE
D000818:Animals; D001059:Apoproteins / Q000737:chemistry*; D007700:Kinetics; D009211:Myoglobin / Q000737:chemistry*; D011489:Protein Denaturation; D017510:Protein Folding; D014508:Urea / Q000737:chemistry*
D001059:Apoproteins; D009211:Myoglobin; C010857:apomyoglobin; D014508:Urea