%A Rishu Jain
%A Deepak Sharma
%A Rakesh Kumar
%A Rajesh Kumar
%O Copyright of this article belongs to OUP.
%J Journal of biochemistry
%T Structural, kinetic and thermodynamic characterizations of SDS-induced molten globule state of a highly negatively charged cytochrome c.
%X This study presents the structural, kinetic and thermodynamic characterizations of previously unknown submicellar concentrations of SDS-induced molten globule (MGSDS) state of a highly negatively charged base-denatured ferricytochrome c (UB-state) at pH ?12.8 (?0.2). The far-UV CD, near-UV CD, ANS-fluorescence data of UB-state in the presence of different concentrations of SDS indicate that the submicellar concentrations of SDS (?0.4 mM) transform the UB-state to MGSDS-state. The MGSDS-state has native-like ?-helical secondary structure but lacks tertiary structure. The free energy change (?G?D) for UB? MGSDS transition determined by far-UV CD (?2.7 kcal mol-1) is slightly higher than those determined by fluorescence (?2.0 kcal mol-1) at 25?C. At very low SDS and NaCl concentrations, the MGSDS-state undergoes cold denaturation. As SDS concentration is increased, the thermal denaturation temperature increases and the cold denaturation temperature decrease. Kinetic experiments involving the measurement of the CO-association rate to the base-denatured ferrocytochrome c at pH ?12.8 (?0.2), 25?C indicate that the submicellar concentrations of SDS restrict the internal dynamics of base-denatured protein.
%N 2
%K alkali molten-globule, constrained dynamics, entropic stabilization, SDS, thermal stability
%P 125-137
%V 165
%D 2019
%I Oxford University Press 
%L open2182