creators_name: Jain, Rishu
creators_name: Sharma, Deepak
creators_name: Kumar, Rakesh
creators_name: Kumar, Rajesh
type: article
datestamp: 2019-03-16 12:06:19
lastmod: 2019-03-16 12:06:19
metadata_visibility: show
title: Structural, kinetic and thermodynamic characterizations of SDS-induced molten globule state of a highly negatively charged cytochrome c.
ispublished: pub
subjects: QR
keywords: alkali molten-globule, constrained dynamics, entropic stabilization, SDS, thermal stability
note: Copyright of this article belongs to OUP.
abstract: 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 α-helical secondary structure but lacks tertiary structure. The free energy change (ΔG°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.
date: 2019-02-01
date_type: published
publication: Journal of biochemistry
volume: 165
number: 2
publisher: Oxford University Press 
pagerange: 125-137
refereed: TRUE
issn: 1756-2651
official_url: https://academic.oup.com/jb/article/165/2/125/5146343
citation:   Jain, Rishu and Sharma, Deepak and Kumar, Rakesh and Kumar, Rajesh  (2019) Structural, kinetic and thermodynamic characterizations of SDS-induced molten globule state of a highly negatively charged cytochrome c.  Journal of biochemistry, 165 (2).  pp. 125-137.  ISSN 1756-2651