01524nas a2200157   4500008004100000022001400041245009700055210006900152260000800221300001400229490000800243520094500251100001901196700002401215856012701239       2019                        eng d  a1520-610600aSlow motion protein dance visualized using red-edge excitation shift of a buried fluorophore0 aSlow motion protein dance visualized using rededge excitation sh  cFEB  a1256-12640 v1233 a<p>It has been extremely challenging to detect protein structures with a dynamic core, such as dry molten globules, that remain in equilibrium with the tightly packed native (N) state and that are important for a myriad of entropy-driven protein functions. Here, we detect the higher entropy conformations of a human serum protein, using red-edge excitation shift experiments. We covalently introduced a fluorophore inside the protein core and observed that in a subset of native population, the side chains of the polar and buried residues have different spatial arrangements than the mean population and that they solvate the fluorophore on a timescale much slower than the nanosecond timescale of fluorescence. Our results provide direct evidence for the dense fluidity of protein core and show that alternate side-chain packing arrangements exist in the core that might be important for multiple binding functions of this protein.</p>
1 aMishra, Prajna1 aJha, Santosh, Kumar  uhttps://library.ncl.res.in/content/slow-motion-protein-dance-visualized-using-red-edge-excitation-shift-buried-fluorophore