title: Solvation dynamics of a protein in the pre molten globule state.
abstract: The nature of solvent molecules around proteins in native and different non-native states is crucial for understanding the protein folding problem. We have characterized two compact denatured states of glutaminyl-tRNA synthetase (GlnRS) under equilibrium conditions in the presence of a naturally occurring osmolyte, l-glutamate. The solvation dynamics of the compact denatured states and the fully unfolded state has been studied using a covalently attached probe, acrylodan, near the active site. The solvation dynamics progressively becomes faster as the protein goes from the native to the molten globule to the pre molten globule to the fully unfolded state. Anisotropy decay measurements suggest that the pre-molten-globule intermediate is more flexible than the molten globule although the secondary structure is largely similar. Dynamic light scattering studies reveal that both the compact denatured states are aggregated under the measurement conditions. The implications of solvation dynamics in aggregated compact denatured states have been discussed.
authors.affiliation: Department of Biophysics, Bose Institute, P 1/12 CIT, Scheme VIIM, Kolkata 700 054, India.
authors.forename: Soma
authors.initials: S
authors.lastname: Samaddar
authors.forename: Amit Kumar
authors.initials: AK
authors.lastname: Mandal
authors.forename: Sudip Kumar
authors.initials: SK
authors.lastname: Mondal
authors.forename: Kalyanasis
authors.initials: K
authors.lastname: Sahu
authors.forename: Kankan
authors.initials: K
authors.lastname: Bhattacharyya
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Roy
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry*; D007700:Kinetics; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry*
chemical_list: D011506:Proteins; D012997:Solvents; D000604:Amino Acyl-tRNA Synthetases; C020659:glutaminyl-tRNA synthetase