Jain, RSharma, DKumar, RakeshKumar, Rajesh2019-09-032024-08-132019-09-032024-08-132019Jain, R., Sharma, D. and Kumar, R., et.al.Structural, kinetic and thermodynamic characterizations of SDS-induced molten globule state of a highly negatively charged cytochrome c.165(2).PP.125-137.10.1093/jb/mvy0870021924X10.1093/jb/mvy087https://kr.cup.edu.in/handle/32116/2447This 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 basedenatured ferricytochrome c (U B -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 (≤0.4mM) transform the UBstate to MG SDS -state. The MG SDS -state has nativelike α-helical secondary structure but lacks tertiary structure. The free energy change (ΔG° D) for U B → MG SDS 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 MG SDS -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. © The Author(s) 2018. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.enAlkali molten-globuleConstrained dynamicsEntropic stabilizationSDSThermal stabilityArticlehttps://academic.oup.com/jb/article/165/2/125/5146343