Fig. 10: Summary of key conclusions.
From: Interactions between the protein barnase and co-solutes studied by NMR
Barnase is shown as an electrostatic surface (blue=positive, with the active site at center right), surrounded by solvent. The energy well represents the extent of fluctuations within the solvent (and because of slaving, also within the protein). Added osmolyte is mainly excluded from the protein surface and leads to a reduction in fluctuations which stabilizes the protein. Added Hofmeister kosmotropic anion (eg sulfate) similarly is excluded and produces a reduction in fluctuations; in addition, it binds to the protein surface and so changes the overall change on the protein (background color). Added chaotropic anion (eg thiocyanate) is less excluded and also binds to the protein surface, producing a change in charge and an increase in fluctuations.
