Femtosecond study of partially folded states of cytochrome C by solvation dynamics.
Using femtosecond time-resolved fluorescence spectroscopy, it is shown that the solvation dynamics in the two partially folded states (IS' and IS' ') of a protein, cytochrome C, are very different. In the case of IS' (formed by the addition of 2 mM sodium dodecyl sulfate, SDS) almost the entire dynamic solvent shift of coumarin 153 (C153) is captured in a picosecond setup and the contribution of the ultrafast component (0.5 ps) is very small (5%). Solvation dynamics of IS' ' (formed by 2 mM SDS and 5 M urea) displays a major component (47%) of 1.3 ps. This indicates that the structure of IS' ' is much more open and exposed compared to that of IS'. The difference in the dynamics of IS' and IS' ' is attributed to differences in their structure, particularly near the heme region, and the presence of urea in IS' '.
Sahu
Kalyanasis
K
Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India.
Mondal
Sudip Kumar
SK
Ghosh
Subhadip
S
Roy
Durba
D
Sen
Pratik
P
Bhattacharyya
Kankan
K
D045304:Cytochromes c / Q000737:chemistry*; D017510:Protein Folding; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D014508:Urea / Q000737:chemistry
D012997:Solvents; D012967:Sodium Dodecyl Sulfate; D014508:Urea; D045304:Cytochromes c