Solvent-Exposed Salt Bridges Influence the Kinetics of α-Helix Folding and Unfolding

Solvent-Exposed Salt Bridges Influence the Kinetics of α-Helix Folding and Unfolding

Salt bridges are known to play an essential role in the thermodynamic stability of the folded conformation of many proteins, but their influence on the kinetics of folding remains largely unknown. Here, we investigate the effect of Glu-Arg salt bridges on the kinetics of α-helix folding using temperature-jump transient-infrared spectroscopy and steady-state UV circular dichroism. We find that g...

Unfolding and Folding of the Three-Helix Bundle Protein KIX in the Absence of Solvent

Electron capture dissociation was used to probe the structure, unfolding, and folding of KIX ions in the gas phase. At energies for vibrational activation that were sufficiently high to cause loss of small molecules such as NH3 and H2O by breaking of covalent bonds in about 5% of the KIX (M + nH)(n+) ions with n = 7-9, only partial unfolding was observed, consistent with our previous hypothesis...

Dynamic Surface Activity by Folding and Unfolding an Amphiphilic α-Helix

We describe a rationally designed peptide with tunable surface activity, where the dynamics of surface activity are an outcome of helical folding. Our rationally designed model peptide is surface-active only as an alpha-helix. We apply circular dichroism to show that the folded population can be controlled with changes in electrolyte concentration, and we apply pendant bubble tensiometry to exp...

Photocontrolled folding and unfolding of a collagen triple helix.

Pressure-induced protein-folding/unfolding kinetics.

We use an off-lattice minimalist model to describe the effects of pressure in slowing down the folding/unfolding kinetics of proteins when subjected to increasingly larger pressures. The potential energy function used to describe the interactions between beads in the model includes the effects of pressure on the pairwise interaction of hydrophobic groups in water. We show that pressure affects ...