CHANGES IN ENERGY FROM THE UNFOLDED TO FOLDED STATE
- Native state of a protein is more energetically favorable than its unfolded state.
- The number of residues in the native state increases as the protein folds.
- Proteins go sharply from being completely folded to unfolded (folding intermediates are unstable).
- Protein folding is "all or none": proteins fold via cooperative transition ? loss of stability in one part of the structure disrupts the bonds, and the entire structure collapses.
- Molten globule form: protein lacks the stabilizing interactions to hold it together.
Protein Folding Dynamics
Protein Folding Dynamics
- The molecular dynamics of protein folding: proteins use a cooperative folding method to go from their unfolded state to their native or folded state; thermodynamics plays a role in achieving a folded protein.
KEY FEATURES OF PROTEIN FOLDING
- Protein folding begins co-translationally.
- Alpha helices and beta sheets are amphipathic
- The interior of a protein has exclusively hydrophobic side chains.
- Changes in free energy dictate this directionality: from unfolded ? folded.
- The unfolded state: helix formation and hydrophobic collapse begins.
- The total entropy associated with the protein decreases as it approaches its folded state: a wide range of unfolded states, only a single native, folded state for the protein exists.