FCCC LOGO Faculty Publications
Capaldi AP , Shastry MC , Kleanthous C , Roder H , Radford SE
Ultrarapid mixing experiments reveal that Im7 folds via an on-pathway intermediate
Nat Struct Biol. 2001 Jan;8(1) :68-72
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Many proteins populate partially organized structures during folding. Since these intermediates often accumulate within the dead time (2-5 ms) of conventional stopped-flow and quench-flow devices, it has been difficult to determine their role in the formation of the native state. Here we use a microcapillary mixing apparatus, with a time resolution of approximately 150 micros, to directly follow the formation of an intermediate in the folding of a four-helix protein, Im7. Quantitative kinetic modeling of folding and unfolding data acquired over a wide range of urea concentrations demonstrate that this intermediate ensemble lies on a direct path from the unfolded to the native state.
20577278 1072-8368 Journal Article